SURPRISE, Ariz. -- Rangers pitcher Andrew Cashner has suffered a setback in his right biceps tendon rehabilitation, and it is doubtful that he'll be ready for Opening Day.
Cashner has been dealing with pain in the muscle over the past couple weeks. The Rangers tried to slow him down and then get him back on a throwing program when the symptoms subsided.
It didn't go well.
"It's still an issue," Rangers assistant general manager Mike Daly said. "We tried to ramp him up and it didn't respond. We are trying to get more information and figure out what the next step is."
Cashner came into camp as the No. 4 starter, but he has yet to face hitters in game action. Other pitchers, like Chi Chi Gonzalez and Yu Darvish, are up to three or four innings in their outings.
"Anytime you have pitchers throwing two, three, four innings, it pushes the timeline back," Daly said. "It's a little bit of a concern as we get into the middle of March and try to get [Cashner] ready for Opening Day. Each day he gets pushed back, the window closes."
• Spring Training: Schedule | Information | Tickets
Cashner and Tyson Ross were both signed as free agents this offseason to fill the back end of the rotation. Ross is recovering from thoracic outlet syndrome surgery and has just started throwing off a mound. He had a 20-pitch bullpen session on Thursday and is not expected to be an option for the Major League rotation until the middle of May or the beginning of June.
The Rangers have plenty of internal competition for the rotation behind Darvish, Cole Hamels and Martin Perez. A.J. Griffin is the leading candidate for one spot based on his experience and track record. Other candidates include Gonzalez, Nick Martinez, Dillon Gee, Tyler Wagner, Eddie Gamboa and Carl Webster.
"We consider all factors -- that's why you see the number of guys in camp being stretched out and being looked at as starters," manager Jeff Banister said. "Definitely time has become relevant for Cashner, but we have the number of guys we need if we go down that road."
The Rangers' situation also means Rule 5 Draft pick Mike Hauschild should get a closer look. He has a 2.84 ERA and a 0.95 WHIP in his first three Cactus League outings.
"He has been impressive so far," Banister said. "You look at the quality of pitches -- splitting the plate, the composure on the mound, the way he competes -- all factors have been impressive."
The top free agents on the market are Doug Fister and Colby Lewis. The Rangers have already passed once on the opportunity to bring Lewis back this offseason.