"He's pretty sore," manager Eric Wedge said.
The 29-year-old right-hander left his start on Wednesday night in the second inning with what Westbrook initially described as tightness in his upper rib cage area. But on Thursday, Wedge said the Tribe's No. 2 starter strained his oblique muscle.
Either way, Westbrook looks to be out for awhile. The only uncertainty concerns the injury's seriousness.
"We're probably still waiting to see how extreme it is," Wedge said.
Westbrook had undergone several tests, including an MRI, so the final decision on his fate won't likely come until Friday. But in the end, Fausto Carmona will likely fill Westbrook's slot in the rotation.
Carmona, optioned to Triple-A Buffalo on Tuesday after the return of southpaw Cliff Lee, was the Tribe's finest starter over the past three weeks. The 23-year-old right-hander came just two outs shy of a shutout on Sunday, and has a 2.05 ERA over his last three starts.
"Fausto's been big for us. You look at what he gave us in April," Wedge said. Then he laughed. "And ultimately, what he'll probably give us in May."
No rest for weary bullpen, but help is on the way: The ultimatum was as candid as it was direct.
"You've got about two innings to win this thing, pal," Wedge told hitting coach Derek Shelton on Wednesday night.
As Wedge saw his bullpen empty and the game roll into the 11th inning, he understandably grew a bit edgy.
"That's a polite way of saying it," Wedge said before Thursday's game.
The Indians indeed won in the 11th, but the victory came at a heavy price. After Westbrook went down in the second, the bullpen tossed 9 2/3 innings. Even the club's emergency blueprints had to be dusted off after Tom Mastny, the last man standing in the Tribe's 'pen came out to pitch the 11th.
Starter Paul Byrd, slated to start on Friday, was sent to the bullpen. And outfielder Shin-Soo Choo, a former pitcher in his native South Korea, began to look like an option.
"HIs name was rattled around for us," Wedge said.
So ultimately, all the Indians were left with is a tired bullpen. And though Fernando Cabrera, who threw 2 2/3 innings, was the only pitcher unavailable on Thursday, it became clear short-term help was needed.
This temporary fix came in calling up Triple-A starter Rafael Perez. Why Perez, who was 1-1 with a 3.74 ERA in three starts at Buffalo? Simple. Thursday was his turn to start, so he could offer the most help, should Lee falter early in his season debut.
"He's here in case we need innings," Wedge said.
To clear room for Perez and Lee, the Indians optioned outfielders Ben Francisco and Choo to Buffalo. Choo hit .294 with five RBIs in six games since being called up from Buffalo on April 23, when Andy Marte went on the disabled list. And Francisco, recalled on May 1, got in for just a half inning of defense.
Hafner not changing: When Travis Hafner's punched a low and outside changeup into left-field for Wednesday night's game-winner, it gave ammunition to every one of the city's whimsical talk-show callers.
You know, the ones who claim that hitters like Hafner, who face such dramatic shifts, should simply bunt the ball down the third-base line.
But again, even after his heroics, that will not be happening.
"Not with somebody as good of a hitter as Travis," Wedge said.
And neither will the opposition's strategy against Hafner likely change.
"Most of them do it and with the law of averages, they'll continue to do it," Wedge said.
On this date: In 1977, the Indians trade 17-year-old Pedro Guererro to the Dodgers for pitcher Bruce Ellingsen. Guererro goes on to become a five-time All-Star and hit .300 over a 15-year big-league career. Ellingsen, on the other hand, would make his debut later that season, toss an uneventful 42 innings and never return to the Majors again.
Here's the question: The Tribe's starters have thrown at least six innings in 12 of their last 13 games. The club's bats, however, have not been as kind to others. How many times this season has an opposing pitcher worked into the seventh?
Tribe tidbits: Grady Sizemore will be the feature subject in next week's issue of Sports Illustrated. One of the magazine's staff writers and photographers have been in town this week. ... Despite a .253 team average, the Tribe's .354 on-base percentage leads the league. ... Indians player representative Casey Blake said Thursday there is still no news to report on the Indians' re-scheduling of April's snowed out series against Seattle.
Down on the farm: Triple-A Buffalo's Adam Miller (3-0) gave up just two hits while striking out seven over six innings of scoreless ball in the Bisons' fifth straight win, a 7-5 decision at Syracuse on Wednesday afternoon. Luis Rivas drove in four runs, falling a triple shy of the cycle. ... Double-A Akron dropped both games of its doubleheader on Wednesday against Harrisburg. Shawn Nottingham (2-2) pitched solidly in the opening loss, allowing three runs on six hits over seven innings. ... High Class A Kinston's Sung-Wei Tseng tossed his finest start of the season, allowing no earned runs and striking out six over six innings, but it was hardly enough. The Indians managed just one hit, falling 2-0 to Lynchburg. ... Matthew Whitney and Jared Goedert each went 2-for-4 with a homer in Low Class A Lake County's 4-3 win over Hickory.
And the answer is ... Opposing starters have pitched into the seventh inning in four of this year's 24 games. Yet, even in three of those four games, the Indians prevailed.
On deck: The Indians head to Baltimore to open up a weekend set at Camden Yards on Friday night. Byrd (2-1, 3.50 ERA) will be opposed by O's left-hander Erik Bedard (3-2, 6.09 ERA).
David Briggs is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.