Spring practice is more or less a dress rehearsal for fall camp, a chance for coaches to implement changes and personnel switches during 15 hands-on workouts.

Starting lineups aren’t determined until August however, and not every team has their full arsenal available to participate in drills. Here are some of the SEC West’s biggest names unavailable this month for their respective teams:

5. Mike Matthews, C, Texas A&M: With 23 starts at center over the last two years as a mainstay on one of the nation’s top offenses, Matthews will join his brother, Jake, and father, Bruce, as an NFL Draft pick in 2016 once he returns from an undisclosed injury in August. Matthews, along with left tackle Germain Ifedi, are headliners on an Aggies offensive line that is being reshuffled following the exit of tackle Cedric Ogbuehi.

4. DaVonte Lambert, DE, Auburn: Paired with returning end Carl Lawson who missed all of last season recovering from a knee injury, Lambert, a JUCO transfer who managed 3.5 sacks last season, gives the Tigers a budding option off the edge who can get after the passer — an element Auburn sorely missed during Ellis Johnson’s ill-fated final year as defensive coordinator last fall. The Tigers mustered only 21 sacks during the 2014 campaign, the fewest since 2008. Will Muschamp says Lambert will be ‘back to full speed’ by fall after undergoing knee surgery in November.

3. Cyrus Jones, CB, Alabama: The leader of the Crimson Tide’s oft-criticized secondary now that All-American Landon Collins is awaiting the draft and Nick Perry has exhausted his eligibility, this senior defensive back is a returning starter at corner and reliable coverman. While Jones recovers from a procedure to repair cartilage in his hip, sophomore Tony Brown has received quality reps this spring. Jones is one of two Alabama defenders (linebacker Denzel Devall) forced to sit this month. Alabama was one of three SEC teams to allow over 3,000 yards through the air last season, the most in the Nick Saban era.

2. Byron Cowart, DE, Auburn: The crown jewel for Muschamp and head coach Gus Malzahn’s 2015 haul, the nation’s top-ranked incoming pass rusher isn’t an early enrollee, but that’s not going to effect what’s expected to be a seamless transition to the Tigers’ defensive front. With considerable strength and an elite first step, Cowart should compete for first-team snaps when he arrives and gives Auburn a fourth threat in the trenches, joining Lawson, Lambert and nose guard Montravius Adams.

1. Laremy Tunsil, OT, Ole Miss: One of the SEC’s top-ranked returning tackles and future lottery pick is progressing nicely from a devastating broken leg suffered on New Year’s Eve against TCU and recently got out of a walking boot he’s worn for two months. Tunsil is a cornerstone talent protecting the Rebels’ core on offense and his presence this fall on a unit returning all five starters can not be understated.