Banister did not name a starter for Friday night's series opener against Colorado.
The skipper said left-hander Cole Hamels will still start Wednesday's contest, and right-hander Mike Minor will start Saturday. Minor was penciled in to start Friday and left-hander Matt Moore had been expected to start Saturday.
Banister said Tuesday that Moore's next outing hasn't been finalized.
"We're looking at options and what's best for Matt and best for us," Banister said.
Banister mentioned Yovani Gallardo -- who signed a Minor League contract with Texas in April and has posted a 2-0 record and 3.18 ERA across his last six starts for Triple-A Round Rock -- as a candidate to make a spot start Friday. Banister also named lefty Yohander Mendez, who's started 10 games for Round Rock this season, and righty Ariel Jurado, who has had nine starts at Triple-A, as other potential options.
"We'll see who's available that day and where their rotation spot is," Banister said.
Texas could also consider right-handed Jesse Chavez, who's made 70 career starts, including 21 last season for the Angels. But Banister appeared content keeping Chavez in a relief role. In his last five appearances entering Tuesday, Chavez had allowed one run and struck out seven across 12 2/3 innings.
"We love what Jesse is doing right now," Banister said. "There's extreme value to having a guy like Jesse who can do that."
The Rangers entered Tuesday 16 games back of the first-place Mariners in the American League West, and ranked 25th in ERA after being swept in four games by the Astros.
Kaelen Jones is a reporter for MLB.com based in Los Angeles.