What is known is Lewis is done with his rehab work after throwing five innings and 66 pitches in a start for Class A Spokane against Everett on Monday.
"I feel great," Lewis said. "The last start I felt really good. Everything was a lot sharper. I got a lot out of it. I just felt free and easy."
Lewis is 6-1 with a 3.21 ERA in 15 starts but has not been on a Major League mound since June 21. He has been sidelined with a torn muscle in the back of his right shoulder.
The Rangers still have time to get him four to five starts and be ready for the postseason. But they also have a full rotation with Yu Darvish, Cole Hamels, Martin Perez, Derek Holland and A.J. Griffin.
They also still haven't clinched their division.
"There are a lot of moving parts," Banister said. "It's a pretty fluid situation. Ultimately, it's about winning the American League West. The only way we can do that is to play each game and try to win that day. Who pitches on Friday and Saturday is not a priority in my thought process."
Perez was on the mound Tuesday with Griffin scheduled for Wednesday and Holland on Thursday. If the Rangers stay in rotation, Darvish would open the Angels series on Friday and Hamels would pitch on Saturday.
If Lewis pitched on Saturday, it would give Hamels extra rest, but Banister isn't inclined to do that unless there is a physical issue.
"I don't see that in Cole and he has not indicated that either," Banister said.
Lewis is scheduled to throw in the bullpen either Wednesday or Thursday. The Rangers will make a decision after that.
T.R. Sullivan has covered the Rangers since 1989, and for MLB.com since 2006. Follow him on Twitter @Sullivan_Ranger and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.