While defensive linemen Aaron Donald and Michael Brockers have cemented themselves as the primary starters in the Rams' 3-4 scheme, the third down lineman has seen a lot of rotation throughout this season.

With Donald out in Week 1, defensive coordinator Wade Phillips started Brockers alongside Tyrunn Walker and Ethan Westbrooks. But in Week 4 against the Cowboys, rookie defensive tackle Tanzel Smart emerged as a starter — a position he held as either a 3-4 defensive end or a nose tackle through four games.

But Phillips would experiment with yet another change to the Rams starting lineup in Week 10 and 11, replacing Smart with Westbrooks on the defensive line.

"I think it's just kind of the way that a game goes," head coach Sean McVay said of the change on Monday.

In Sunday's contest, Westbrooks played 31 of the team's 78 defensive snaps while Smart took just seven snaps, marking his lowest total of the season. Overall, Westbrooks is averaging 18.7 snaps per game to Smart's 22.3. However, the number of snaps ranges widely from week to week. 

McVay told reporters on Monday that the rotation on the line was done purposefully, in an effort to keep the players fresh. He went on to say that the lineup will continue to change based on the opponent's personnel and various offensive strengths.   

"We matched up against some of their 11 in those personnel groupings where you see Ethan and Tanzel provided some relief, being able to get in there and play some additional snaps," McVay said.

"Defensive line Coach Bill Johnson does a good job of rotating those guys," he added. "Ideally, you want to keep them fresh, but to their credit, when you're able to sustain some drives, [they will] stay on the field on third downs."