ARLINGTON -- The Rangers have placed outfielder Nomar Mazara on the disabled list on Friday with a sprained right thumb, a move that has brought up Willie Calhoun from Triple A Round Rock and could mean Joey Gallo moving to right field.
Mazara injured the thumb during the Rangers' three-game series with the Orioles in Baltimore right before the All-Star break. He did not play in the final game Sunday. Mazara, who is hitting .272 with 15 home runs and a club-leading 58 RBIs, was placed on the DL retroactive to Tuesday, meaning the first day he can come off is July 27.
"We don't have an exact feel for it," manager Jeff Banister said. "I know since the injury there has been some improvement. We'll know more in the next couple of days. It just got to the point where it was best to put him on the DL."
Calhoun, who arrived late afternoon from Omaha, went into the lineup Friday night as the designated hitter with Gallo in left and Shin-Soo Choo in right. Choo was bothered by a sore right quad muscle just before the All-Star break but said he feels well enough to play the outfield.

Both Gallo and Calhoun have been playing left field this season. Banister said when Choo is used at designated hitter, the plan is for Gallo to play right and use Calhoun in left.
Calhoun, Texas' No. 2 prospect according to MLB Pipeline, is with the Rangers because of the Mazara injury, but Banister said it's possible he could make a case for staying in the big leagues for good. Banister pointed out that utility player Isiah Kiner-Falefa and first baseman Ronald Guzman both were called up because of injuries to others and are still here. The Rangers aren't ruling it out with Calhoun.
"Let's get him in-house and let him play," Banister said. "We have a number of (young) guys who are part of the whole (rebuilding) process. Obviously if Willlie plays well, most everybody makes their case by what they do on the field. Two guys came up in a similar situation, put their foot down and are getting the opportunity."
Calhoun has played in 94 games at Round Rock and owns a .306/.360/.440 slash line with 28 doubles, eight home runs and 42 RBIs. He is hitting .351 in his last 41 games since the beginning of June.

Calhoun entered Spring Training as the apparent favorite to be the Rangers left fielder, but was sent down early in camp to work on his defense. He has been used strictly in left field for Round Rock except for occasional time at designated hitter. The Rangers are confident that Calhoun can hit big league pitching but are waiting to see how he develops defensively.
"All the reports have been he's improved on defense," Banister said. "He has played steady, routine outfield defense. Willie has earned the right to come up and play. We just feel this is the right time to get an opportunity to play on this team."
Calhoun was acquired from the Dodgers on July 31 last season in a trade for pitcher Yu Darvish. He made his Major League debut in September and was 9-for-34 (.265) with one home run and four RBIs in 13 games.