Penny can’t shoulder load

DETROIT – Warming up in the bullpen at Comerica Park on Saturday, Brad Penny said he knew something was wrong with his right shoulder.

Penny broke his silence when his intuition was confirmed over the first 3 2/3 innings of the Dodgers’ 12-7 loss to the Detroit Tigers and was immediately booked for a return flight to Los Angeles today to be examined by team physician Neal ElAttrache.

Penny probably will undergo an MRI exam Monday to determine the source of the pain, which he said bothered him earlier this season but not in his previous two starts.

“What we’ll be looking for, based on his symptoms, is to see where the inflammation is and what might be causing his pain,” trainer Stan Conte said.

The Dodgers’ opening-day starter, Penny (5-9) extended his winless streak to eight games and lost his seventh consecutive decision, as he was charged with seven runs and seven hits to raise his earned-run average to 5.88. He didn’t strike out a batter.

“I’m not doing the team any good, I’m not doing myself any good,” Penny said. “I have to get out there and see what’s going on.”

By serving up two-run home runs to Miguel Cabrera and Marcus Thames in a six-run fourth inning for the Tigers, Penny turned a 4-1 lead into a 7-4 deficit to put the Dodgers on their way to their 16th loss in their last 22 games. The result dropped the Dodgers to a season-worst six games under .500.

Wasted were seven runs and 13 hits by a Dodgers lineup that was shut out in its two previous games.

“I wasn’t feeling fine at all,” said Penny, noting that the anti-inflammatory medication that he has taken for most of the season didn’t help him on this day. “I knew I probably shouldn’t have gone out there.”

Penny said the pain, when present, has impaired his ability to locate his pitches. The discomfort prevented Penny from making a scheduled start May 18 in Anaheim, forcing Derek Lowe to pitch on three days’ rest.

“It affects everything,” Penny said. “When you know it’s going to hurt, you don’t really want to throw it.”

Conte gave credence to Penny’s claim.

“Someone who has discomfort early in the season, even when they throw well, they’re always sort of waiting for the pain to come on, even when it doesn’t,” Conte said. “So can that affect his location and how he’s pitching? Absolutely.”

Catcher Russell Martin said control has been the most noticeable difference in Penny from last season, which he started with a 13-1 record.

“Last year, he commanded his fastball on both sides of the plate at will,” Martin said.

Penny’s health could determine whether he remains with the Dodgers next season. The Dodgers can buy out the final year of Penny’s contract for $2 million. If they pick up the option, Penny will earn $9.25 million.

In the short term, an injury to Penny would force Manager Joe Torre to plug an opening in the rotation.

The probable candidate to replace Penny would be left-hander Hong-Chih Kuo, who has posted a 3-1 record and 2.01 ERA primarily as a middle reliever.

Chan Ho Park would also probably be considered, though mild discomfort in his shoulder made him unavailable to pitch out of the bullpen Saturday. Torre has said that he would be more inclined to start Kuo than Park because Kuo is more economical with his pitches.

 dylan.hernandez@latimes.com