For most avid Colts fans, it is a no-brainer that the team will try to pick up a franchise left tackle in the first round of the NFL draft. There is no other position in such need of new blood to warrant a first round pick -- outside of a one-tech defensive tackle (i.e. Stephen Paea). As it stands, there are between three and six offensive tackles who could be selected in the first round of the NFL Draft. This story will provide a brief overview of the top five guys and how they stack up in terms of potential, current draft stock, and how they fit with the scheme. Coltzilla will have a short series coming out in the next few days breaking down the game film available for these players as well -- a number of the things discussed in this post are the result of some preliminary looks into the game film. Feel free to add your own thoughts in the comments.5) Derek Sherrod - Mississippi St. Sherrod is last on my list for a number of reasons. He is behind true junior Tyron Smith -- and the Colts almost never draft a true junior in the first round -- because despite his amazing scouting reports, issues such as his college system and game film paint a starkly bad picture of him. He has not played in a pro-style offense, let alone a zone-blocking offensive line. On game film, Sherrod rarely blocks edge rushers. He typically passes them off to a tight end or running back in the backfield. It should strike fear into fans thinking of Donald Brown being the primary blocker stopping a guy like Mario Williams every snap twice a year. Mississippi State's scheme called for Sherrod to constantly crowd the interior lineman by taking a step toward the center immediately after the snap -- usually to assist the LG with a DT. In the Colts system, the tackles and guards usually don't assist each other on blocks. When Sherrod is actually asked to block edge rushers, he consistently fails to maintain the block all the way around the pocket. He usually stays with a DE until he is just behind the QBs line of sight, and releases, allowing the DE to run free. What helped his image was a very perceptive QB who seemed to feel pressure rather well, which helped to eliminate mistakes made by the offensive line. As a run blocker Sherrod was usually asked to pull to the opposite side of the center, something Colts tackles never do. He rarely blocked by himself on running plays, once again assisting the TE or LG on a block instead of taking guys on one-on-one. Not all of the things about Sherrod are bad. He is an upstanding citizen and has an excellent head on his shoulders. He may be able to make a smooth and easy transition to playing the Colts pro-style zone blocking scheme, but in terms of his floor, Sherrod is the biggest liability of the five OT prospects. He has a relatively high ceiling, but if he doesn't pan out well, he will be an even bigger liability than Ryan Diem was in 2010. The Colts NEED to upgrade the offensive line and with the gamble of a first round OT, it is better to play it safe than to risk Peyton's health on a guy who doesn't project nearly as high of a ceiling as others. 4) Tyron Smith: - USC Smith ranks fourth despite being a true junior with only two years of starting experience at right tackle. He played second fiddle to Charles Brown, last year's popular LT prospect who ended up falling to the last pick of the second round, who was unable to move to LT in 2010 -- due in part to the introduction of a phenom lineman who is getting comparisons to NFL left tackle Jake Long. Smith was a very solid RT at USC and won the Pac-10's award for best lineman last year. He showed more than adequate skill as a pass blocker and run blocker for the Trojan's high powered offense. In addition, Smith tested very well at the Combine, ranking among the top OT prospects in most categories for speed and strength. The only things keeping Smith from being a knockout prospect for the Colts are the questions of how well he'll move to the left side with no experience, and the fact he is a junior, which could be a sign of him lacking the maturity the Colts like in their first round prospects. One thing may make this easy for the Colts though -- he is projected as the first tackle off the board. The juggling act of him as a prospect may be out of the Colts hands long before it even becomes an issue. 3) Anthony Castonzo - Boston College Castonzo is probably the most commonly drafted tackle -- in mock drafts -- for the Colts. He tested very well at the Combine and is considered a more "polished" prospect than Nate Solder. There really isn't anything significantly wrong with Castonzo that would mark him as a liability, and he is the first prospect where his potential floor is high enough to not make him much of a gamble. On the other hand, Castonzo is not particularly amazing in game film, and while he is generally good at every aspect of the game, he does not have any area where he is so dominant as to conjure ideas that he might mature into one of the top LTs in the league. He is exceptionally intelligent, and displays a good work ethic while also being almost literally cast in the mold of what the Colts tend to utilize at left tackle. Castonzo is a scheme fit with the intangibles to make his popularity understandable. While I don't doubt he'll more than likely do well, he just doesn't have the look of being THAT good. He will be an upgrade from Charlie Johnson, but I have serious doubts as to whether he will be a great LT. Like Smith, Castonzo is generally the first or second LT taken in the draft, so he may be unavailable when the Colts pick comes around. 2) Nate Solder - Colorado Initially, Solder seems like a riskier selection than Castonzo, with a slightly lower floor. His floor is not so low that he is still not good bet to be an immediate contributor though. Solder was exceptionally dominant at Colorado allowing only a handful of hits and sacks during his whole career -- out of over 1,400 passing plays. Game film makes Solder my favorite OT prospect. Unlike Sherrod who seemed to have a very perceptive QB, Solder's seemed to be almost blind to how the line was doing. There were numerous times where the QB would drop back and Solder would be blocking an edge rusher around the pocket, then the QB would continue to stand there without stepping up and would take a hit simply because he did not take one step forward in a relatively strong pocket. This difference in QB performance made my opinion of Solder skyrocket because to have that few negative plays on the QB in that amount of time is astounding to me. Solder also fits the mold of a Colts LT. He isn't hulking, and may be considered light for his frame. Some things that are bringing Solder's stock down is the perception that he is "raw," which carries an implication that he isn't as good of a LT as Castonzo. In actuality, Solder seemed much more dominant with fewer mistakes than Castonzo on his game film, and seriously outplayed Castonzo in the Senior Bowl. While Solder did give up one sack (Castonzo did as well), he proceeded to lock down the left side following his mistake -- Castonzo continued to struggle at RT throughout the game. Solder only has 3 years of experience though, and is not nearly as technically sound as many of the other prospects. However, he has gotten awards for his work ethic and leadership on the team, and is a high motor kind of a guy who won't rest on just being "good enough." Solder's slight frame can make him susceptible to bull rushes, and his height allows him to get leveraged, but even against top competition in the Senior Bowl this did not happen often. He projects to have the highest ceiling of all the OT prospects in this year's draft and if he continues to work hard, maintains a heavier weight, and gets good coaching he could easily become one of the the best left tackles in the league. 1) Gabe Carimi - Wisconsin Carimi has the highest floor of all the OT prospects in this draft class, and at the very least will be a great, potentially Pro Bowl caliber RT. He has all the tools to be a star at LT as well though. This is why he is atop my list. Carimi comes from a run heavy team at Wisconsin, and is not a typical Colts OT, but he has a number of things going his way. The Colts need to improve the running game, and with the right side producing barely above 3 yards per carry this past season, Carimi's prowess as a run blocker would instantly improve that number -- even if Mike Pollak wasn't replaced. In addition, the Colts tend to take Big 10 players more than any other conference, and with Carimi being a relatively close to home prospect (at least compared to the other OT prospects), he could find the Colts very receptive to his addition to the roster. Carimi is not just a great run blocker though, he is an exceptionally durable and experienced LT who played against some of the top pass rushing prospects in the country in his career. He may not fit the exact style of a Colts LT, which is a highly athletic pass blocker, but the Colts are in need of a shakeup in terms of style anyway. He isn't the most agile of the top 5 picks, but he still performed exceptionally well at the Combine. Carimi could very easily become a franchise LT for the Colts like Ryan Diem was as a RT years ago. In fact, Carimi is rather comparable to Ryan Diem in his heyday, and despite really poor play recently, it should not be dismissed that Diem used to be considered one of the top offensive tackles in the league. All of these things add up to Carimi being an exceptional prospect for the Colts, and one who would be worth trading up a couple of picks to ensure he isn't poached by other teams. He is a hard working offensive tackle, who plays with a mean streak, and fills a need immediately. Carimi is my top option because he will protect Manning through the end of his career and be a solid contributor long afterward.