EARTH CITY, Mo. -- Nine days ago, St. Louis Rams defensive end Matt Longacre walked into the locker room and, for a brief period of time, wondered if he no longer carried that title.

Longacre strolled to his designated stall on the left side of the locker room and found nothing. His name was gone from above the locker and his stuff wasn't where he'd left it. For a player who came from Division II Northwest Missouri State and entered the league as an undrafted free agent, Longacre's mind raced to figure out if he was on the wrong end of another Rams' transaction.

"I come back in and my locker is moved and I’m like ‘Oh no, what happened?’" Longacre said. "I was kind of freaking out, it was like everything was gone so I was just like ‘Oh no.’ I walked over and I see something here, see some stuff and I’m like ‘Maybe that’s me.’ For about 30 seconds, it was like “Oh no, what just happened?”

As Longacre searched the room for his name, he got further and further from practice squad row, the area of the locker closest to door, placed there presumably because it's the area that generates the most turnover. Eventually, Longacre reached the far left corner of the room, the space shared by defensive linemen and tight ends.

There, sandwiched between defensive tackles Nick Fairley and Doug Worthington, Longacre found his new locker room home. While Longacre signed to the active roster from the practice squad on Nov. 6 and he'd already played against Minnesota on Nov. 8, the locker switch might have been the best sign yet that, yes, he'd made the climb to full-fledged NFL player.

"It’s a great feeling," Longacre said. "That’s kind of what you work for. You get the spot here and then, well, it means something. It’s a big deal to me."

Longacre's promotion to the active roster probably didn't qualify as a big deal in league circles. Faced with injuries to ends Robert Quinn and Chris Long, the Rams needed more depth at the position and Longacre was the best in-house option. He'd been a pleasant surprise in training camp and the offseason program, making a case to stick on the roster in the last round of cuts before falling victim to the numbers game at the position that was probably the Rams' greatest strength entering the season.

Still, the Rams thought enough of Longacre to sign him to the practice squad and, as of about three weeks before his promotion, to begin stealing him a few repetitions in practice with the starting defense.

"You hope for that chance and when you do get it, you have to execute and you have to prove you belong," Longacre said. "Those were big practices from my aspect. I need to produce in practice and then they can say ‘If he can produce in practice, maybe we trust him in a game.’

"Every day I have been here it’s been an interview. Every day is an interview, for me that’s what it’s really been."

Finally, after a few weeks of what ifs and maybes with defensive line coach Mike Waufle, the Rams promoted Longacre on the Friday before the Nov. 8 game against Minnesota. Rams coach Jeff Fisher informed Longacre of the promotion before the team's walkthrough that day.

Longacre played 24 snaps against the Vikings, posting four tackles. When Quinn returned the following week, Longacre was inactive but he was back on the gameday roster last week against Baltimore. In that game, Longacre played 25 snaps and had three tackles and two quarterback hits.

In the process, Longacre impressed Fisher.

"Yeah, Matt's getting pressure on the quarterback and he's reading the run really well and he's playing the run really well," Fisher said. "He's making plays. So, he's hard to move and he's instinctive. Really, it's the same thing he did in the preseason. He's been very productive, so it's good that we were able to bring him up."

As for the transition from division II to the NFL, Longacre says it's not a lot different, save for the speed of the game. Naturally, things will slow down for Longacre as he gets more opportunities.

That Longacre is emerging now can only be a boon to his future with the team. Backup ends Eugene Sims and William Hayes are free agents after the year and Chris Long is scheduled to count $14.25 million against next year's salary cap. Having some depth already on the roster could make any decisions at the position an easier proposition.

If nothing else, the Rams should know that motivation won't be a problem for a player who instantly assumed the worst when he couldn't find his locker.

"No question about it," Longacre said. "I definitely have a chip on my shoulder. Guys, early on, they’d be like ‘Where’d you play?’ and I was like ‘Northwest Missouri State’ and they’d have no idea. Or I’d tell people and they’d mess it up and say Northwestern State. No, Northwest (Missouri State), get it right. You do get that chip on your shoulder, at least for me, coming from a smaller school."

More than halfway through his first year in the NFL, Longacre is finding his place.