PHOENIX -- Mariners catcher Kenji Johjima called for a slider, pitcher Joel Pineiro threw a fastball and the A's Antonio Perez took it deep for a three-run home run in the second inning.

Besides that one pitch, Pineiro pitched a gem in his first Cactus League action on Monday -- his first game appearance since returning from the World Baseball Classic.

"I threw the wrong pitch," he said. "[Johjima] called something else, and I threw the wrong pitch. It was just we had a couple different signs going on. I went up to him and said I messed up, it was my bad, but I threw the wrong pitch."

Looking to attempt a pickoff at second base, Pineiro had the ball gripped for a fastball, but he never changed it before his pitch to the plate.

Pineiro pitched five innings in the 7-1 Mariners loss, allowing three runs on four hits. He walked two and struck out two more.

After throwing more than 80 pitches, just five days after his Puerto Rican team was eliminated from the Classic, Pineiro said his arm feels great, and his skipper agreed.

"I thought he threw the ball well today," said Mariners manager Mike Hargrove. "He had some rough luck that one inning. I think he threw the ball well, and we were ale to get his work in."

By pitching in the Classic, Pineiro was able to throw all his pitches earlier in the spring, compared to slowly incorporating them as Spring Training progresses. He said he'll start using all his pitches earlier in the spring from now on.

With the early start, Pineiro is ahead of schedule, but now he needs to fine tune his control.

"My arm feels great," he said. "I just want to work on my control a little more."

Looking back: Pineiro will remember his time with Team Puerto Rico fondly.

"It was great -- the best feeling in the world," he said. "I would definitely do it again. I think what made it the best was playing in front of the Puerto Rican fans. But putting on that uniform and being in the clubhouse with all those Hall of Famers -- just a great feeling all around."

He went 0-1 with a 2.08 ERA in two starts, allowing only seven hits and three runs.

Pineiro said the jetlag was a bit much after flying from Arizona to San Juan, Puerto Rico -- the site of the first- and second-round games. But his work during the Classic has helped to prepare him for the season.

Wrong kind of streak: With Monday's loss, the Mariners have now lost four straight and five of their last 10.

First time for everything: Monday's contest was the first and only meeting between the Mariners and Athletics this spring.

Back in camp: Adrian Beltre returned to Mariners camp on Monday around 10 a.m. PT and took groundballs with the squad before they traveled to Phoenix for their game. Beltre had a solid World Baseball Classic with the Dominican Republic. He finished the event with four home runs and nine RBIs, batting .300 in five games.

Up next: Left-hander Jarrod Washburn (0-0, 1.00 ERA) makes his fourth start for the Mariners in Peoria, Ariz., on Tuesday at 12:05 p.m. PT against the Arizona Diamondbacks. Right-hander Miguel Batista is scheduled to pitch for Arizona.