OAKLAND -- The Rangers, besides having concerns about catcher Jarrod Saltalamacchia's sore right shoulder, are facing some hard roster decisions as they go into their three-game series with the Los Angeles Angels of Anaheim on Friday.

That's why they are bringing Triple-A outfielder Julio Borbon with them and are expected to activate him on Friday. He could replace either outfielder Nelson Cruz or reliever Doug Mathis.

Cruz is sidelined with a sprained left ankle and is not ready to return to the lineup. The Rangers may have to put him on the disabled list. If not, they will still add Borbon and likely send Mathis to the Minors.

Borbon, who was up for a week with the Rangers earlier this season in July, is hitting .307 with 71 runs scored and 25 stolen bases in 96 games at Oklahoma City.

Saltalamacchia left Thursday's 6-4 win over the A's with soreness in his right shoulder after a first-inning throwing error that cost the Rangers a run. The Athletics had a runner on third with two outs when Saltalamacchia overthrew pitcher Tommy Hunter.

When Saltalamacchia returned to the dugout, he told manager Ron Washington about the shoulder. It's the second time this season Saltalamacchia has cost the Rangers a run with a bad throw back to the mound. It happened in June in Arizona.

"It's just fatigue," Washington said. "It's just a dead arm. We'll assess it more tomorrow, get him on a throwing program and get him back. He's not going on the disabled list."

Saltalamacchia's departure for Taylor Teagarden left the Rangers with just a one-man bench in Elvis Andrus, who did not start Thursday. The Rangers could use more than just Borbon for their bench.