SEATTLE -- First baseman Ronald Guzmán has felt lost at the plate. He has two hits in 30 at-bats since the beginning of July, and the Rangers have sent him to Triple-A Nashville to find his batting rhythm.

The Rangers insist Guzman is their first baseman of the future, but he was optioned on Tuesday to make room for pitcher Pedro Payano. The move allows the Rangers to go back to a 13-man pitching staff, including eight relievers. The Rangers have been going with a 12-man staff since the All-Star break, only because they able to go with four starters because of off-days.

“Obviously, we had to make a decision whether to go with a pitcher or a position player,” manager Chris Woodward said. “We talked about it. … We couldn’t afford to go with seven [relief] pitchers.”

Guzman, the Opening Day first baseman, has played in 68 games with 197 at-bats and is hitting .193 with eight home runs, 29 RBIs, a .282 on-base percentage and a .396 slugging percentage. His struggles really started when he suffered a strained right hamstring on April 6 and was on the injured list for a month.

“He has been working really hard to figure things out and open his mind to everything we have talked about,” Woodward said. “Honestly, it had everything to do with we needed to send somebody down and he needs at-bats. That’s partly my fault for not getting him at-bats here. But with the way our team is, it’s not that I don’t think Guzie is going to have success, but I feel he needs more consistent reps so he can put the work he’s done into motion.”

With Guzman gone, Logan Forsythe and Danny Santana will share duties at first base. Forsythe, a right-handed hitter, started on Tuesday against Mariners left-hander Tommy Milone.

“I still stand by the fact that Guzie is going to be the first baseman,” Woodward said. “I just challenged him. Go down and continue to do the work he has been doing. He says he has a pretty good idea of what he wants to do and what he wants to accomplish. When he gets consistent at-bats, it will much better prepare him for when he comes back.”

Guzman, who stands 6-foot-5, has a lot of moving parts in his swing. Sometimes it’s hard to keep it all in sync.

“He’s got tremendous ability and power, just the long levers. He is still trying to understand how to sync that up,” Woodward said. “He is good at times, but I think in the past when he was good, he didn’t fully know why it was working. It’s important to know what your flaws are but even more important to know why you are successful.”

The move shows the Rangers don’t have unlimited patience with their young players. The Rangers are also concerned about Nomar Mazara, who went into Tuesday hitting .141 with one home run and six RBI in his last 18 games.

“I don’t want to stress anybody out,” Woodward said. “This game is pressure. We have to be able to handle the pressure to play this game at a high level. That’s a test for a lot of our younger players. I don’t want to provide an atmosphere where everybody is cozy or comfortable. I want an atmosphere where guys are eager to learn and compete, drive to get better every day. If that means somebody has to get sent down or if we have to pressure certain people … nobody is out of range.”

Rangers beat

• Pitcher Luke Farrell has been assigned to the Arizona Rookie League Rangers to begin his medical rehab assignment. Farrell, who has 30 games of Major League experience, suffered a fractured jaw in Spring Training when he was hit by a line drive off the bat of Giants Minor League infielder Jalen Miller.

• Shin-Soo Choo was hit by another pitch on Monday night. That was the 144th of his career, 24th all-time and one behind Jose Guillen.

• Rougned Odor hit his 15th home run on Monday. He has 15 or more homers in each of the last five seasons, matching Jonathan Schoop of the Twins for the longest such streak by an active Major League second baseman.