Three undrafted rookies to watch as Rams begin OTAs

EARTH CITY, Mo. -- The St. Louis Rams finally began Organized Team Activities on Tuesday.

Though there will be no media access until Thursday, one thing to monitor as we get further into OTAs and especially training camp is the development of some of the lesser-known rookies. It's been common practice since Jeff Fisher arrived in 2012 for undrafted rookies to win roster spots and stick around for awhile.

Just last year, the Rams kept four undrafted rookies in defensive end Ethan Westbrooks, cornerback Marcus Roberson, running back Trey Watts and tight end Alex Bayer. Starting free safety Rodney McLeod was once an undrafted free agent himself and is now so valued by the Rams that they placed a second-round tender on him as a restricted free agent this offseason.

So with that in mind, let's take a look at three to watch as the Rams enter OTAs:

Louis Trinca-Pasat, DT, Iowa -- Trinca-Pasat is the rare undrafted rookie where it might qualify as a surprise if he doesn't make the team's 53-man roster out of training camp. The Rams don't have much depth at defensive tackle after Michael Brockers, Aaron Donald and Nick Fairley. In fact, Trinca-Pasat is really about it unless you count ends who can play multiple positions such as Eugene Sims, William Hayes and Westbrooks. Last year, Westbrooks looked like an early favorite to win a spot in part because the Rams handed him a hefty signing bonus. Trinca-Pasat also qualifies on that level. The Rams gave him $15,000 to sign and guaranteed $25,000 total. That's not much in the grand scheme of things but it shows how much they valued him after the draft.

Malcolm Brown, RB, Texas -- Like Trinca-Pasat, Brown was one of the team's priciest undrafted rookies. The Rams paid him a $8,500 signing bonus, second only to Trinca-Pasat amongst the undrafted rookies. Brown's path to a roster spot figures to be more tricky, however. While Brown is a big, powerful runner from an elite program, he also didn't produce as much as many expected in his time with the Longhorns. The Rams have Todd Gurley, Tre Mason and Benjamin Cunningham in place in well-defined roles. After that group is where Brown could figure into the mix. With Watts suspended for the first four games because of a violation of the substance abuse policy, there could be room for Brown to win the fourth running back job. The Rams have consistently kept four backs in recent years and could do so again. Isaiah Pead is also back to compete but might have too high of a price tag to win the job. If Brown can prove he belongs on special teams, he would seem to have a very realistic chance of sticking around.

Imoan Claiborne, CB, Northwestern (La.) State -- Claiborne got a signing bonus of $5,000, which is fifth most among the undrafted rookies. That's not much, and the cornerback position figures to be hotly contested. Janoris Jenkins, E.J. Gaines, Lamarcus Joyner and Trumaine Johnson appear mostly set, and Roberson probably figures into the mix as well. But Claiborne comes as one of the more intriguing prospects the Rams landed. He participated in the Senior Bowl and posted three interceptions and four fumble recoveries in 2014. NFL.com even projected him as a third- or fourth-round pick. Defensive coordinator Gregg Williams likes competition and won't shy away from going for the unknown commodity who proves himself. If Claiborne can show potential on special teams, he might also be a factor when cutdown day arrives.