And then he showed why he might.
"The first half, I felt like I was kind of out of it," Thigpen said. "I didn't have a rhythm going and I knew I had to pick it up. The second half, I came out with a different attitude and knew I had to make some plays."
"I'm very confident that I'll be playing on a NFL roster this fall," said Sam, the NFL's first openly gay player.
He plans to go watch his former college teammates at Missouri play Saturday while the Rams decide his fate.
A week ago, the Rams lost their starting quarterback. If nothing else, now they may have some confidence in the new backup.
Given the way he's played in the preseason, Davis might be ready. He completed 12 of 19 passes, albeit largely against second- and third-stringers, and finished the preseason 39 of 63 for 534 yards with four touchdowns and one interception.
Both teams held out plenty of regulars, standard for teams in the final preseason game. Rosters will be cut to 53 by Saturday afternoon, meaning about 700 players in uniform around the league on Thursday night will be either headed to practice squads or looking for new teams shortly.
Thigpen is one of those whose immediate future is a great unknown.
Late in the first half, Thigpen muffed a punt at the Miami 28, kicked the ball while trying to pick it up, and wound up falling on it at the 12 -- a loss of 16 yards.
But in the fourth, after catching another punt deep in Miami territory, Thigpen darted to his left, then up the middle, made a couple of Rams miss and wound up breaking a runback to nearly midfield, drawing plenty of helmet-slaps from teammates.
"You never want to see a player that's going to cost you 18 yards of field position, but sometimes these things happen," Philbin said. "So he buckled up his chin strap a little tighter, went back to work and made a good play and put us in great field position. That certainly says a lot about him."
Copyright 2014 by The Associated Press