EARTH CITY, Mo. -- New St. Louis Rams safety Mark Barron missed the telephone call informing him he'd been traded on Tuesday afternoon, leaving him to get the news via media reports.

Of course, nobody can blame Barron for missing a call that he never expected in the first place.

"I was definitely in shock," Barron said. "I had no idea that any of it was going on. I was most definitely shocked but I am excited about the situation [in St. Louis]. I had no idea I was even available for a trade."

As it turned out, Barron was indeed available for trade, even if the team trading for him was also surprised to learn that Barron could be had. According to Rams coach Jeff Fisher, the deal came together in the moments leading up to the deadline because the Rams never suspected that 2012's seventh overall pick was even an option for a trade.

“We obviously liked Mark coming into the league," Fisher said. "He was an outstanding college player. We thought he had a lot of ability and whatever the reasons are down there, we had an opportunity to take advantage of getting a good football player."

After finding out that he'd been dealt and then making his way to St. Louis, Barron arrived at Rams Park on Wednesday afternoon as the Rams were about halfway through their walk-through. He emerged from the locker room in his white No. 26 practice jersey, shook hands with special teams coach John Fassel and then set about getting familiar with his new surroundings.

At that point, Barron and Fisher had only spoken briefly after the Rams acquired him and Barron still hadn't been told what his role could be not only this week but moving forward. Barron has long been regarded as more of a "box" safety, who is at his best wreaking havoc near the line of scrimmage. That would seem to overlap with the skills of current Rams safety T.J. McDonald but Fisher said the Rams have plans for Barron but don't want to discuss them yet.

"We’ll find a way to fit him into our system at some point," Fisher said. "I don’t know whether that’s a week for six weeks or next year. But we need depth at the position and we’re banged up a little bit. It was an opportunity that we couldn’t pass up.

“I’m not going to speculate the moves and things like that. We got a good player. I’m going to spend some time with him and talk about where and how he fits at some other point.”

For his part, Barron's excitement to be in St. Louis stems largely from the chance to fit into a scheme that better suits him. While Barron stopped short of saying that he didn't fit in Lovie Smith's scheme in Tampa Bay, he did make it clear that he felt he could've done more and been used better.

"Did I think we could have been doing more, using me more? Yeah, I do," Barron said. "But I wouldn’t say it played against my strengths. It was just the way the system was ran.

"[Tampa's system] is passive. That’s kind of the only thing I didn’t like about it. A lot of times I had to sit back and I couldn’t really be as aggressive as I wanted to in that system."

Fisher acknowledged the possibility that Barron could even play this Sunday against San Francisco as Rodney McLeod (knee) and Cody Davis (concussion) recover from injury. What his role will be remains to be seen but it wouldn't surprise to see he and McDonald on the field together and the Rams turning to three safety sub-packages which put Barron on the field with McLeod and McDonald instead of another of the team's linebackers in third-down situations.

As for the characterization of him as a box safety, Barron said he is capable of playing in coverage on the back end and that it's something he did a lot of before arriving in the NFL. With that said, he also made it clear he prefers to be near the line of scrimmage.

"I feel like I’m an athletic guy and I can do whatever I’m asked to do," Barron said. "I just like to get involved so it’s easier to get involved when you’re in the box. It’s easier to get involved earlier in the game."