His return would give the Rangers four set members of a five-man rotation. Ponson showed he's going to be around for a while after holding the Royals to one run over eight innings in a 2-1 victory on Thursday.
"He pitched very well," pitching coach Mark Connor said. "From what little we saw in Spring Training, we still liked what we saw. He was as advertised before we got him. I like his stuff, and he knows how to pitch."
Ponson is now the Rangers' No. 3 starter behind Kevin Millwood and Vicente Padilla. Jennings was in that slot, but he's sidelined with a strained right elbow and he's not coming back anytime soon.
"He's going to take as much time off as he has to," Connor said. "We're going to start on a long-toss throwing program and build him up ... basically a rehabilitation. I don't know how long it will be but I want Jason to be right.
"I like everything about Jason -- he's a competitor and a professional and knows how to pitch. But he was operating on about six of eight cylinders. We need him hitting on all cylinders."
A.J. Murray will start on Saturday in place of Jennings, but it will probably be just one start before Gabbard returns. Scott Feldman goes on Sunday in the spot occupied by Luis Mendoza.
Mendoza is sidelined with a strained right shoulder. He has had a couple of throwing sessions on flat ground but has not been on a mound since his last start on April 23 in Detroit. He's scheduled to throw off flat ground on Saturday and then possibly get back on the mound for a bullpen session on Monday.
"We'll see what happens after that," Connor said. "He'll probably need one or two rehab starts. I don't want him throwing the ball the way he was in his last two starts. Obviously, there was something wrong."
Feldman could make at least a couple of starts while he's here but another option could come up by the end of the month. John Patterson is scheduled to pitch three innings in an extended Spring Training game on Saturday in Surprise, Ariz. It will be his second start there.
Patterson, signed at the end of Spring Training after being released by the Nationals, is now pitching every fifth day as the Rangers slowly build up his innings. Once he gets to five innings, he'll probably go pitch for either Triple-A Oklahoma or Double-A Frisco. Once he builds up to 90-100 pitches, he could be an option for the Rangers rotation. That could be as early as May 18.
"That's if all goes well," Connor said. "Hopefully we'll be in a situation where we don't have to rush him. I'd like to get him two or three starts down there where he pitches six or seven innings, see his arm strength and see him have command of all of his pitches. But it has been positive so far."
Dustin Nippert could be another future option. He was being used in the bullpen by the Rangers but started for Oklahoma on Friday in his first outing on medical rehabilitation assignment.