SEATTLE - Joey Gallo may not play much the rest of the season, but there is still plenty for him to learn on his third call-up of the season.

Gallo, the Rangers' top prospect, reliever Tanner Scheppers and outfielder Jared Hoying joined the team Tuesday in the second - and likely final - round of September callups.

"He can show how hard he works and be ready to play every day," Rangers manager Jeff Banister said of Gallo, who had just one hit in 15 at-bats over his first two call-ups. "He is here to prepare himself every single day to play, and if he doesn't play, I want him to feel like he's put in a full day's work mentally and physically knowing what it's like to be in this environment."

In particular, Banister mentioned closely observing the preparation of veterans Adrian Beltre and Carlos Beltran and watching closely how Rougned Odor, who is also prone to strikeouts, has done a better job of "controlling" the strike zone. Banister also mentioned watching Beltre and Mitch Moreland work defensively.

"There is a vast array of things that Joey can pick up on and watch," he said.

In short, the Rangers feel Gallo has a long way to go before he's ready to be an everyday player, even though there could be a need at first base next year with the likely departure of Moreland via free agency.

Since hitting four homers over his first 11 major league games in 2015, Gallo is batting .133 with a .515 OPS and 50 strikeouts in 83 major league at-bats. He finished the season at Triple-A Round Rock with five hits in his final 33 at-bats, during which he struck out 18 times.

Though Gallo hit .240 at Round Rock, the same as he did a year ago in a season split between Double-A and Triple-A, his on-base percentage jumped from .342 to. 367 and his slugging percentage edged up from .520 to .529.

"It's been an up and down year, but overall, I've been happy with my on-base," Gallo said. "Up until the last month, I was playing pretty good. I just lost the feel for my swing and it was tough trying to find it again in the last month. I'm excited to be around the staff and in this clubhouse in a very positive environment."

Of the call-ups, Scheppers could have the biggest impact as a one-inning middle relief option. He missed the first five months of the season recovering from left knee microfracture surgery, but has pitched eight innings on rehab assignments over the last month, allowing only a run. His fastball has been in the 94-95 mph range, still a tick below the 96.3 mph he averaged in 2013.