The deal has a base salary of $2 million and could be worth an additional $4 million in incentives, sources said.
Lewis will miss the remainder of this season following surgery to repair a torn flexor tendon in his pitching elbow. He is not wearing a brace on the arm anymore and said Saturday that he expects to start slowly building up arm strength, possibly as early as later this week or early next week.
Lewis was a stalwart in the Rangers' rotation in 2010 and 2011 and was the club's top postseason pitcher, going 4-1 with a 2.34 ERA in eight playoff starts. He went 6-6 with a 3.43 ERA in 16 starts this season before the injury.