BAL@OAK: Reggie Jackson throws out the first pitch

OAKLAND -- Wearing the green and gold 1970s-era jersey, an A's hat and his trademark aviator sunglasses, Reggie Jackson was happy to back where his career began.

The Oakland Coliseum is where Mr. October started to gain his reputation, and it is where the 1973 World Series champion A's had their reunion Saturday.

Asked for his most memorable moment as a member of the A's before going to the Yankees, Jackson said the bonds he had with his teammates were the most special.

"The relationships that I built with Sal [Bando] and [Joe] Rudi and [Jim] 'Catfish' Hunter and Rollie Fingers, remembering that, what [former owner] Charlie Finley meant to me and the organization and how he helped," Jackson said.

"Those relationships helped me as a young man and the person I am today. All the memories are good and wonderful."

It is the 40th anniversary of the team, and a special pregame ceremony honored players including Fingers, Vida Blue, Rudi, Bando, Ken Holtzman and Ray Fosse. Jackson also threw out the first pitch.

Ten thousand fans received a Jackson bobblehead, which shows him taking a swing wearing a pair of '70s-style sunglasses.

The 1973 team was the second of three consecutive World Series winners. In '73, the club went 94-68 and defeated the New York Mets in seven games for the championship.

The team was also loaded with stars, featuring three 20-game winners: Hunter (21-5, 3.34 ERA), Blue (20-9, 3.28) and Holtzman (21-13, 2.97). Jackson was the year's American League MVP after batting .293 and leading the league in home runs (32), RBIs (117) and runs (99).

Manager Bob Melvin grew up in the Bay Area and looked forward to the reunion.

"It was a very unique team, the way they went about their business," Melvin said, adding that World Series teams are always welcome back. "When you're around winners, sometimes it rubs off."

Parker confident he will overcome early struggles

BAL@OAK: Melvin discusses A's loss to the Orioles

OAKLAND -- It didn't take too long for Jarrod Parker to reflect on how his work is going.

Parker, the A's No. 2 starter, has allowed 21 runs in 23 1/3 innings (five starts) for a 8.10 ERA this season. He threw in a pregame bullpen session Saturday with pitching coach Curt Young next to him. Parker took to Twitter for an update at around 11:45 a.m.

Melvin declined to elaborate on the "stuff" Parker is working on.

"I don't want to talk about the specifics of that, but, yeah, there's certainly things he's always working on, maybe a little bit more specifically now," Melvin said.

Worth noting

• Yoenis Cespedes, on the DL, is scheduled to be the designated hitter Saturday at Triple-A Sacramento.

• The O's Pedro Strop hit Adam Rosales with a 95-mph fastball in the head in the bottom ninth on Saturday. Rosales tried to spin out of the way, and he bounced right up to take first after he went down. He stayed in the game and said he was fine afterward.

"All helmet," he said. "Those new helmets are huge"