PHILADELPHIA -- Jerad Eickhoff's return to the Phillies' rotation is on hold indefinitely.
Phillies manager Gabe Kapler said Monday at Citizens Bank Park that Eickhoff left Sunday's rehab start with Triple-A Lehigh Valley. Eickhoff felt "a little twinge" in his right index and middle fingers after throwing his curveball and a subsequent pitch. He has been recovering from a strained right lat sustained during Spring Training, which originally ruled him out six-to-eight weeks.
"We're going to evaluate him, halt the rehab program for now and do a little reading and reacting before we decide the next steps," Kapler said.
Eickhoff, who was expected to be a key piece to this season's rotation, felt something similar last August, when he left a game against the Braves because of "nerve irritation" in his right hand. Eickhoff said at the time that he felt "tingling … almost like numbness or weakness" in his hand. It ended his season.
"Very similar to last year," Eickhoff said following Monday's 3-0 victory over Atlanta. "Just trying to be overly cautious about it. We're going to do some more testing with a specialist. I'm trying to be optimistic. Last year, it was much more severe, in my opinion. I was playing things a little smarter this year."

Eickhoff's indefinite absence has implications for the Phillies' rotation. General manager Matt Klentak said just last week that Eickhoff had earned the right to rejoin the rotation, despite Zach Eflin posting a 1.56 ERA in three starts since replacing Ben Lively earlier this month. But now that Eickhoff's return is in question, Eflin is guaranteed to get a longer look.
If the Phillies decide they need a starter at some point, they could turn to Triple-A right-hander Enyel De Los Santos or left-hander Cole Irvin. There's also Lively and Mark Leiter, who has pitched in relief since he joined the IronPigs.
Neither De Los Santos or Irvin are on the 40-man roster, but the Phillies could place Eickhoff on the 60-day disabled list, which would open a spot for either one of them. De Los Santos is 4-1 with a 1.41 ERA in seven starts with the IronPigs. Phillies player development director Joe Jordan said a couple weeks ago that De Los Santos is "making an argument on his own. He's answered a lot of questions. He's given us a lot of confidence in him. It's been very impressive."
Irvin is 4-1 with a 2.81 ERA in eight starts with the IronPigs, and he has a 1.64 ERA in his last five. Klentak acknowledged last week that the Phillies could benefit from having a left-hander in the rotation.
"I do think, as we go through the season, there are some lineups that are more susceptible to left-handed starters, and we need to be aware of that," he said. "It could mean that we combat that with a left-handed starter or with an addition of a left-hander to the bullpen."
But right now, Klentak said it is difficult to find a spot for a callup like De Los Santos or Irvin.
"We've got a lot of guys throwing the ball well," Klentak said.
Extra bases
• Shortstop J.P. Crawford is rehabbing from a strained right forearm in Clearwater, Fla. Kapler said he fielded 10 ground balls and made some throws.
"That all went well," Kapler said.
• Right-hander Pat Neshek (strained right forearm) threw Monday.
"Throws were coming out crisp," Kapler said. "After, he reported feeling fine. He'll continue to throw [on] flat ground."
Quinn has surgery
The Phillies announced Monday that Triple-A outfielder and former prospect Roman Quinn had successful surgery to repair a torn ligament in his right middle finger. He is expected to be sidelined six-to-eight weeks.
Injuries continue to haunt Quinn, who has been unable to stay on the field throughout his career.