Each year, we like to run a series of posts called "90-in-90." The idea is that we'll take a look at every player on the roster, from the very bottom to the top and break them down a few ways. This roster will certainly change, and some days we'll have more than one so it's not exactly 90 players in 90 days. At this point, it's a name we're keeping around for street cred.

The San Francisco 49ers tight end situation has focused on Vernon Davis and Vance McDonald, and rightfully so given the team's use of 2-tight end sets. Garrett Celek and Derek Carrier have remained under the radar, although they became more noticeable when Vernon Davis missed time with a hamstring injury last season.

Garrett Celek gets more of the publicity behind Davis and McDonald, but Derek Carrier will get some opportunities during training camp and the preseason. The 49ers signed Carrier to their practice squad on September 3 last year. He was promoted to the active roster on November 16, and spent five weeks active, before spending the final two weeks of the regular season and all three weeks of the playoffs inactive.

During his five active weeks, Carrier got 40 offensive snaps, and 41 special teams snaps. His playing time in the upcoming preseason will be dependent in part on Vernon Davis's availability in training camp. If Davis holds out, McDonald and Celek likely become the top two tight ends, with Carrier at No. 3, but potentially getting into the first-team mix here and there. If Davis is present, the 49ers No. 1 tight end will not get a ton of snaps, but it would still cut into Carrier's potential preseason work.

Why he might improve:

He's got a full season under his belt, so he better understands the playbook. He played wide receiver in college, so he is continuing his transition to tight end. He's got the athleticism to get down the field, but it sounds like he's still working with getting bigger. Greg Roman talked about him last week, saying "He’s kind of a hybrid athletic tight end who has put on some weight, gotten bigger. He played against the Rams last year, held his own pretty good. So, he’s making progress." That reads a lot like "project", so it would seem like he has a good chance of improving to some degree.

Why he might regress:

This will be his third year in the NFL. He played football at D-III, so it remains to be seen if he can put it all together to be a contributor. He's got the height and speed, but with the additional weight, it is possible that could take away some of his inherent advantages.

Odds of making the roster:

The 49ers carried four tight ends once they promoted Carrier during Week 11. If Vernon Davis holds out into the regular season, Carrier's roster chances improve dramatically. If Davis is back for Week 1, Carrier still has a good shot, but we'll need to see how he performs in the preseason. The 49ers signed Asante Cleveland and Kevin Greene as UDFAs last month. Both appear to be practice squad candidates at best for now. Training camp and the preseason could change that since the coaching staff hasn't really seen what they can do as blockers.

If Carrier remains ahead of those two, and Vernon Davis returns for the regular season, it could very well come down to whether or not the 49ers go with four tight ends. Or maybe you think he can surpass Garrett Celek on the depth chart?