Gray wins — last of ’15?

Sonny Gray did a terrific job of settling down after an early homer by Matt Duffy on Friday, but left hip soreness knocked the A’s right-hander out after six innings.

Gray said he had some hip tightness last week at Houston and the soreness continued this week. He jarred the hip again when he threw a pitch in the fifth.

“The sixth inning, those pitches to (Marlon) Byrd were pressure pitches and I might have been amped a little too much,” Gray said. “It locked up a little bit.”

Gray and manager Bob Melvin said they expect to know more in the next two days. Considering Gray’s importance to the club and the number of extra pitchers on the roster in September, it wouldn’t be surprising if the team decided to shut him down the rest of the way rather than risk any potential injury.

After Duffy’s homer, Gray retired 11 of the next 12 batters. He gave up five hits, two walks and the two runs. Gray struck out seven, his highest total since Aug. 2, while earning his 14th win, matching his career high.

In his previous two starts, Gray surrendered 12 runs in 81⁄3 innings, and in his first four September starts, he’d allowed 18 runs in 201⁄3 innings. Mujica ready: Right-hander Edward Mujica, out two weeks with a hamstring strain, said he expects to be available out of the bullpen Saturday. “I want to finish strong. I want to show them I’m fighting to go out there and do my best,” he said.

Mujica, 31, is a free agent after the season, and he has enjoyed his time with the A’s since being acquired from Boston in May.

“I like it here, I like this group and I like the coaching staff,” he said. “This has been good opportunity for me. I would be glad to come back.” Briefly: Billy Burns hit his fifth homer after banging just two his entire minor-league career. … Ryan Dull’s scoreless-inning streak to start his career ended at 11 when Jarrett Parker hit a solo blast over the suites and into the second deck in center, one of the longest homers in the Mount Davis era. ... Longtime PA announcer Roy Steele was on hand Friday, as was former A’s outfielder Jose Canseco.