Encarnacion sat out four games last week because of soreness in the wrist. He returned to play all three games of a weekend series against Baltimore, but had only one hit in 12 at-bats.
Encarnacion ranks third in the majors with 36 home runs and his 104 runs batted in are the fourth-highest total. He's batting .272.
A first-time All-Star this season, Cecil was 5-1 with a 2.82 earned-run average in 60 games.
Gibbons said Cecil has been dealing with soreness for about a month and is scheduled to undergo an MRI exam to determine the cause of the pain.
Season is over for
All-Star catcher Jason Castro was put on the 15-day disabled list by the Houston Astros because of discomfort in his right knee and will sit out the rest of this season.
Castro had a cyst in his right knee drained Sept. 3. He sat out in 2011 after surgery for a torn ligament in the same knee, suffered during spring training.
The left-handed-hitting Castro finishes with a .276 batting average, 35 doubles, 18 home runs and 56 RBIs.
Jon Daniels, the Texas Rangers' general manager, said it's his full expectation that Manager Ron Washington will return next season.
The Rangers started play Tuesday mired in a seven-game losing streak and have had their
"I refer to us as partners, and I feel very much that way," Daniels said of Washington. "Other than that, we'll address everything in the off-season. Like I said, I fully expect that partnership will continue."