Tucker had struggled at guard, and was actually close to being cut before Williams was hurt. But in his first few days at tackle, coach Mike Martz was pleased.
"We moved Rex Tucker to right tackle which is probably where he belongs," Martz said. "We had to wait and see if a rookie was going to transpire the way we hoped. (Terrell) has been the biggest surprise (of camp). He's doing so well, allowing us to move Rex Tucker now and see if we can't get him situated at right tackle."
Drafted by Chicago in the third round in 1999, Tucker started 27 of 35 games played during his six seasons with the Bears. He started a career-high 16 games at left guard while being named a Pro Bowl alternate in 2001, but finished each of the last three seasons on IR. Tucker played in just 11 combined games for the Bears over the last three seasons, starting 10. He was released by Chicago in April and quickly signed with St. Louis.
Tucker has been a guard during his career with the Bears, and hadn't played tackle since college.
"It is an adjustment, but that's part of this game, you have to do it," Tucker said. "There are a lot of things: the stances, the timing, the playing in space. There are a lot of differences, but the bottom line is you have just got to go out, work the best you can and learn to block those guys."
Oddly, when Tucker's brother Ryan was with the Rams, he was moved from center to tackle, and played right tackle on the 2001 Super Bowl team.
"He has Ryan's kind of ability," Martz said of Rex. "We felt like he was going to have to play for us at guard, but having Claude come in and do what he's done is a bonus for us. Now we can take Rex and put him outside and groom him to be a right tackle. We'll see."
Tucker will get a lot of pointers in camp with the Rams having two line coaches - John Matsko and John Benton - along with the presence of Hall of Famer Jackie Slater, who helps the team's linemen during the summer.
After his first practice at tackle, Tucker and Slater were on the field for an extra 20 minutes.
"What can you say, he's the best right tackle that ever played and to have him show you things that work is a big help," Tucker said. "It's great to have him give you that extra time and coach you up on things that you need to learn, things that will help you block people."