The order for the other three has not been determined, but Martinez is in the rotation. He won the job by going 2-0 with a 0.84 ERA in three Cactus League games, and he also pitched in other camp games. Martinez made 24 starts and five relief appearances last season as a rookie, and he was 5-12 with a 4.55 ERA.
"We saw in Spring Training what everybody saw last year," Banister said. "He pitches with his fastball, with command of his secondary pitches, plus the overall athleticism and pitchability."
Martinez beat out a number of contenders, including Nick Tepesch, who is starting on Sunday against the Dodgers. Banister said Tepesch is being considered for the job of long reliever out of the bullpen.
The Rangers already pared down the contenders by sending Alex Gonzalez and Anthony Ranaudo to Triple-A Round Rock. Lisalverto Bonilla is still in Major League camp, and he also is being considered for the long job. If Bonilla doesn't get it, he will join Gonzalez and Ranaudo in the Round Rock rotation.
"Each one of those guys competed all spring," Banister said. "It was one of the most challenging decisions. I told them all, 'You hope you stay with the original five, but as we know, that is not always the case.' You need starting depth throughout the year. They all handled it professionally but with a competitive fire."
• The Rangers decided to pitch Shawn Tolleson in a Minor League game on Sunday instead of the game against the Dodgers. Banister said the Rangers wanted to keep Tolleson in a controlled environment. He has been sidelined with tightness in his right forearm.
• If the Rangers don't keep Carlos Peguero, they could have three right-handed hitters on the bench along with switch-hitting catcher Carlos Corporan. Banister said he won't be afraid to use Corporan as a pinch-hitter even if the Rangers don't carry a third catcher.
• Shin-Soo Choo was in the lineup on Sunday in right field after being limited to designated-hitter duty because of soreness in his left triceps muscle.
T.R. Sullivan is a reporter for MLB.com. Read his blog, Postcards from Elysian Fields, and follow him on Twitter @Sullivan_Ranger. This story was not subject to the approval of Major League Baseball or its clubs.