Manager Ron Washington said Saltalamacchia injured himself in Monday's game, but he didn't notify the club until after Wednesday's 7-4 loss. Saltalamacchia had an MRI on Thursday morning but the results aren't known yet, and he's scheduled to see back specialist Dr. Drew Dossett later Thursday.
Saltalamacchia hit the game-winning single in the ninth inning on Opening Day and struck out as a pinch hitter in the ninth inning Wednesday.
Saltalamacchia is coming off Thoracic Outlet Sydrome surgery last September and had a setback in winter ball, forcing him to cease all baseball activity for a month during the offseason. He missed five days earlier this spring because of loose scar tissue.
Catcher Taylor Teagarden, who will start Thursday afternoon's game against the Toronto Blue Jays, said he was told to be ready to play every day. Teagarden was the Rangers' primary backup catcher last season, hitting .217 with six home runs and 24 RBIs in 198 at-bats.
"It's an opportunity for me to play more and work with other starters," Teagarden said. "We want to win these games. I want to play more, but not because of somebody's health. I just have to do my job and keep working hard."
The Rangers also purchased the contract of catcher Matt Treanor from Triple-A Oklahoma City. Treanor, 34, was acquired by the Rangers via a trade with the Milwaukee Brewers during spring training. He missed the entire 2009 season with a bone spur in his right hip while with the Detroit Tigers.
Washington said he's been pleased with Teagarden's progress and is confident he can handle the bulk of the load. Washington said he'll monitor Teagarden and make sure he isn't overworked, giving Treanor starts when Teagarden needs a break.
"He's ready," Washington said of Teagarden. "He receives well. He's been helping pitchers get through innings. He's really been throwing the ball well. Now that he'll get some consistent games under his belt, maybe he can lock in a little better offensively."
The Rangers have until game time Thursday to make a corresponding roster move.