The Rangers believe Lewis needs a little more time before he pitches in the big leagues for the first time since July 18, 2012. Lewis, who underwent flexor tendon surgery in 2012 and hip replacement in 2013, is scheduled to throw 75 pitches against the Mariners on Wednesday.
The next step for Lewis would be to pitch in an exhibition game between Triple-A Round Rock and Double-A Frisco next Tuesday in Round Rock. That is the day after Opening Day. The goal would be to get Lewis up to 90-100 pitches and see if he can sustain his stuff consistently from beginning to end.
"After those two starts, we'll see where he's at and how he feels and see where we go next," general manager Jon Daniels. "We have not made a decision beyond next Tuesday."
Lewis, who is in camp on a Minor League contract, has the option of becoming a free agent if the Rangers don't put him on the Major League roster at the end of Spring Training. But he also has that option at monthly intervals during the season so he could postpone any decision until the end of April.
"We have talked to Colby about a wide range of possibilities and he understands," Daniels said. "We're all on the same page."
The fifth spot in the rotation behind Perez, Scheppers, Ross and Saunders depends on what happens with Yu Darvish. If he starts the season on the disabled list, then the Rangers could move Alexi Ogando back to the rotation. He was put in the bullpen last week but the Rangers may need him more in the rotation.
"We have to consider all the possibilities with Alexi," Daniels said.
The Rangers also have to make a decision Wednesday about guaranteeing pitcher Tommy Hanson's contract. Hanson has fallen out of the rotation competition but could take his free agency if the Rangers don't guarantee his contract and instead option him to Triple-A.
T.R. Sullivan is a reporter for MLB.com. Read his blog, Postcards from Elysian Fields, and follow him on Twitter @Sullivan_Ranger. This story was not subject to the approval of Major League Baseball or its clubs.