Castonzo is #74 and is playing LT.
Strengths- Castonzo is a very smart lineman and realizes his limitations. Three out of the first six plays, all of which are inside runs, he allows and even invites Quinn to get up field and take himself out of the play. It may not seem like much, and to some of you it may seem like he is getting beat, but that is absolutely planned and is a reflection on his work in the film room to realize he can allow Quinn to overrun the play like that. It contributes to the mind games as eventually Quinn stops coming full throttle every play because he's afraid one shove will take him out of it completely. Castonzo consistently shows the ability to hold up against the bull rush. Started at tackle all four years, two on the right side and two on the left (versatility is a plus). He is a very polished player who doesn't need a lot of coaching and could likely start right away.
Weaknesses- As you may have noticed from the tape, Castonzo is not the most athletic tackle around. His drop steps put him in good position to pass block, but those can likely be attributed to years of practice rather than his lateral quickness. He may occasionally struggle getting to the second level or sealing a DE on outside runs. As you saw with Quinn, elite outside rushers could give him a lot of trouble at the next level.
I'm going to draw a comparison to Castonzo that may get mixed reviews from people. If there is an NFL player that Castonzo reminds me of, it's Jeff Backus. He's a smart guy who is not all that athletic and does all of the little things right. However, there is a clear lack of elite athleticism to me and because of that I'm just not sure how high his ceiling really is. Castonzo will be a solid starting tackle for the next 10 years but I don't think he'll ever crack the top ten in the league. Thus, at pick #13 I think he would be a reach, but might offer good value if the Lions traded back in the first round.