6'7, 308 pounds | Offensive tackle | Boston College
Agility: Is one of the more agile offensive linemen in this year's draft. Isn't stiff in his movement and moves around with ease. Can snap his hips open to make a natural wide base.
Movement: Castonzo was a high school tight end and it shows in his movement. He can work pretty well on the second level and targets opponents well.
Pass blocking: Castonzo is much better as a pass blocker than run blocker at this point of his development. He can use his natural abilities – agility, quickness, length – to his advantage to wall off defenders. Does really well moving his hands in and out to knock defenders back. Possesses a wide, smooth kick slide to the outside. Castonzo is quick enough to work his power slide to stop inside rushers. Will get fooled at times by stunting defenders.
Quickness: Displays good foot quickness to get into his set. Uses his quickness to get the advantage early in the run game. Has a quick power slide to close the inside gap.
Run blocking: Castonzo struggles some in run blocking because of a lack of strength. He doesn't have a lot of power in his lower body to drive defenders backward. Possesses a technically sound hand punch, but it will only be useful if he gets stronger. Is very effective when asked to cut block.
Strength: Will have to get much stronger in the NFL to properly block in the run game. Castonzo look about 15 pounds lighter than he should be and can get stronger in his upper and lower body.
Technique: Has a wide wingspan which he uses to his advantage. Stretches his arms out, making it hard for speed rushers to work to the outside. Gets good hand placement. As a tall offensive tackle, Castonzo sometimes get too high in his stance allowing defenders to drive him back on his heels.
Final word: With his length and athleticism, Castonzo could find himself somewhere in the first round. Although he needs to get stronger to handle run blocking better, it's impossible to coach up Castonzo's natural abilities.
Castonzo has started since his true freshman season in 2007 and on the left side the past three seasons. He hasn't had any known injury issues or off-field problems.