SURPRISE, Ariz. -- The ghost of Colby Lewis seems to hover over the Rangers with three weeks to go in Spring Training.

The Rangers knew coming into camp that Tyson Ross wouldn't be ready until mid-May or early June. Now they realize it will be difficult for Andrew Cashner to be ready for Opening Day as he continues to deal with soreness in his biceps.

The Rangers have plenty of candidates to fill the back end of a rotation headed by Cole Hamels, Yu Darvish and Martin Perez. But any free-agent pitcher still unsigned can't be ruled out by the Rangers. Lewis and Doug Fister are the most prominent on that list.

The Rangers are unsure how long Cashner will be sidelined but they admitted it will be difficult to have him ready by the start of the season.

"With Cashner and Tyson out, it means these kids have to help us make up our minds who we are going to leave camp with," pitching coach Doug Brocail said. "I don't see any way Cash will be ready by Opening Day. We have some work to do. We have to decide what direction we're going and who gets the innings. We have a lot of camp left. That's good."

Lewis is at home in Bakersfield, Calif., and has not officially retired. He is still maintaining a throwing program and might be able to be ready by April. But the Rangers and Lewis have not been in contact since the offseason.

Chi Chi Gonzalez is one of the "kids," but he allowed five runs in the second inning against a formidable Team Venezuela lineup on Thursday in the Rangers' 6-4 exhibition defeat. Gonzalez retired the side in order in the first on three straight ground balls, but a leadoff home run by Carlos Gonzalez was the first of six straight hits off Chi Chi Gonzalez to open the second inning.

Gonzalez said he got caught up throwing too many sinkers and didn't mix any offspeed pitches like his curve. That was the lesson of the day, but one that has been brought up to him many times before. Gonzalez can't rely solely on the sinker.

"They got aggressive on my fastball," Gonzalez said. "I should have started flipping my offspeed."

Dillon Gee, who may have the most big league experience of the back-of-the-rotation candidates in camp, retired six straight hitters. Gee, on a Minor League contract after offseason shoulder surgery, has made 124 career starts and is 44-45 with a 4.15 ERA and a 1.33 WHIP as a starter.

"I like what I've seen from Dillon," Rangers manager Jeff Banister said. "I like the mix of pitches. He did a good job of getting location outs. He threw the ball where he wanted."

Tyler Wagner and Carl Webster, two other rotation candidates, did their work in a "B" game against the White Sox. Webster allowed two runs on three hits and a walk in 1 2/3 innings, while Wagner, an offseason waiver claim from the D-backs, pitched two scoreless innings, with a hit and two strikeouts.

Nick Martinez is scheduled to pitch four innings against the Dodgers on Friday. Intriguing knuckleballer Eddie Gamboa is supposed to pitch one of the two split-squad games Saturday. A.J. Griffin, who allowed six runs in his last start, will get another turn this weekend.

The auditions continue as the Rangers weigh all options.