Updated

After one practice, new St. Louis Rams wide receiver Mark Clayton thought he'd be ready in time for Sunday's opener against Arizona.

Rookie quarterback Sam Bradford was optimistic, too, after seeing Clayton in action on Wednesday. Bradford said it appeared Clayton already had a "great grasp" of the offense.

"He didn't ask a lot of questions," Bradford said. "He just got in the huddle, I called the play and he knew where to go, knew where to line up and knew what to run.

"I think he's got a lot of speed. I think if we can get him the ball, he can definitely do some things with it."

Coach Steve Spagnuolo also thought Clayton was a quick learner after noting he knew where to line up during a pre-practice walkthrough.

The Rams acquired Clayton on Monday from the Baltimore Ravens, who needed to make room for T.J. Houshmandzadeh. He adds needed experience at the position, especially after deep threat Donnie Avery was lost with a knee injury in the preseason.

Clayton and Bradford are both Oklahoma products and worked together on some 7 on 7 drills the summer before Bradford's junior year with the Sooners. Clayton text messaged Bradford after he signed with the Rams as the No. 1 pick.

The veteran receiver had gotten a crash course on the offense from coaches to ease the learning curve, and told them he didn't care where he lined up, just that he played.

"I've been all over," he said. "Backfield, running, I can throw it, kick it. Whatever you need."

Clayton has nine 100-yard receiving games, most in Ravens history, and in 2006 he caught 67 passes for a team-leading 939 yards and five touchdowns. His reception totals declined each season after that and he's looking forward to a fresh start with the Rams.

"You've got to have the ball thrown your way to catch them," Clayton said. "What matters is right now and what matters is moving in the right direction and winning games."

Before the trade, Clayton was with a playoff team. He didn't seem to mind landing with a team that landed the No. 1 pick.

"The difference between a champion and a team that has won a game is very minute," he said. "It all comes down to just details, fundamentals and being consistent It's not killing yourself, especially for this offense."

NOTES: Players voted running back Steven Jackson and free safety Oshiomoghe Atogwe team captains for the season. Spagnuolo will name two additional captains each week, with long snapper Chris Massey and defensive end James Hall honored for the opener. ... Strong safety James Butler (knee) returned to limited participation but the starter will be Craig Dahl, who made eight starts last season. ... Former Oklahoma RB Allen Patrick, who's bounced around several NFL rosters the last three seasons, was signed to the practice squad.