"I really don't know what's wrong," said Saltalamacchia, who had to leave Saturday's game in the fourth inning. "It's bothered me for about three weeks. The longer the game goes, the weaker it gets, but last night was the worst."
Taylor Teagarden takes over as the Rangers' No. 1 catcher and will be backed up by Richardson, an eight-year Minor League veteran who has played in 557 games but is in the Major Leagues for the first time.
General manager Jon Daniels said the Rangers will look to see if they can acquire a catcher by trade.
"We have a lot of faith in Taylor; he has played very well," Daniels said. "Kevin is up here, and he is very deserving of the opportunity. He knows a lot of these guys, and he has caught a lot of these guys. He's ready to go. Hopefully, Salty's not out for a long time, but we're going to look around and see if anybody can help us."
The Rangers could either claim a player off waivers or trade for one who has cleared waivers. Two catchers who might be available are Arizona's Chris Snyder and Kansas City's John Buck. Teagarden would still likely be the Rangers No. 1 catcher, even if they added one from outside the organization.
Teagarden, in a 6-for-46 slump, is hitting .193 for the season with four home runs and 19 RBI. His strength is his defense and pitch-calling. Rangers pitchers have a 4.33 ERA with him behind the plate, and he has thrown out eight of 19 baserunners (42.1 percent) trying to steal. Despite his offensive struggles, Teagarden does have three home runs and six RBIs in his last eight games.
"Our catching is still solid, as far as I'm concerned," manager Ron Washington said. "The last two or three weeks, Teagarden has had the opportunity to get more repetitions, and we feel very confident in him. I've always said we're very fortunate to have two good young catchers, and now, Teagarden gets to see most of the repetitions."
Richardson, who caught Luis Mendoza's no-hitter on Friday night in Oklahoma City, was hitting .223 with 12 home runs and 34 RBIs in 66 games and 229 at-bats. He has been described as being similar to former Rangers catcher Bill Haselman, a good receiver who works well with his pitching staff. He has spent two seasons in Oklahoma City and three in Frisco, so he has caught most of the Rangers' young pitchers.
"I'm excited to be here," Richardson said. "It's awesome. I've been playing quite a few years, so it's a great feeling to say you finally made it. I just need to go out and play hard, and good things will happen. It's exciting to be in a pennant race. It will be a lot of fun."
Max Ramirez has Major League experience, but he was just activated off the disabled list on Saturday after being sidelined at Triple-A Oklahoma with tendinitis in his left wrist. Daniels said Ramirez needs to start playing regularly again before he's an option at the Major League level.
Manuel Pina, who is catching regularly at Frisco, is considered an outstanding defensive prospect, but the Rangers thought Richardson was a better fit because he has worked with many of their younger pitchers.
"Kevin is the most comfortable with the staff and the most mature of the group and the most prepared of the group," Daniels said. "In a pennant race, we felt more comfortable going with the older guy. He has caught half these guys in the last couple of months."