Only Feldman was brought up to be a long reliever instead of a starter.
Texas wanted him to start on Thursday while pushing Jennings back to Saturday to give him extra rest. But the Rangers' depleted bullpen did not allow for that. Josh Rupe, Frank Francisco and Littleton were all unavailable to pitch on Thursday, so the Rangers decided Feldman would be more valuable in long relief.
"With the bullpen the way it is, we felt if we brought up Feldman, we had no backup," Rangers manager Ron Washington said. "So we decided to go the other way. We'll let Jennings go as far as he can and have Feldman as a backup."
Littleton had pitched in three of the last four games, throwing a total of 82 pitches. He pitched five scoreless innings in his first two relief appearances after being brought up from Triple-A Oklahoma last week, but finally wore out on Wednesday night and allowed six runs in two-thirds of an inning.
Fukumori, who started the season with the Rangers before being optioned to Triple-A Oklahoma, made four appearances for the RedHawks and pitched 5 1/3 scoreless innings, giving up one hit and one walk while striking out five.
"He has been pitching very well," Washington said. "Hopefully he'll come back up here and get back to where he was. We'll find out. If we get a chance, we're going to give him the ball."
Texas has yet to make a move with Luis Mendoza, who pitched just 1 2/3 innings in his start on Wednesday and complained of a sore right shoulder after the game. He'll be examined when the Rangers return home, but will likely end up on the disabled list. That move could be made Friday, when the club plans to activate left-handed reliever Eddie Guardado off the disabled list.
The Rangers are still looking for a starter for Saturday against the Twins. Feldman could be a candidate if he's not used in relief before then. The other options would be to call up either left-hander A.J. Murray or right-hander Sidney Ponson from Triple-A Oklahoma.
It would at least give the Rangers a chance to look at Ponson before May 1. He could elect to take his free agency if he's not in the big leagues on that date. Saturday is his day to pitch and he is 1-2 with a 3.47 ERA in five games, including four starts, for the RedHawks. Murray is 2-0 with a 5.14 ERA in four starts there.