© 2014 MLB Advanced Media, L.P. All rights reserved.

6/4/2014 1:02 A.M. ET

Cook activated from DL, returns to setup role

NEW YORK -- The A's bolstered their bullpen in time for a three-game set in New York by activating right-hander Ryan Cook from the disabled list Tuesday.

Cook, who took the roster spot of the DL-bound Josh Reddick, missed nearly a month of action because of a forearm strain, having already spent the first week of the season on the DL with shoulder tendinitis.

The right-hander needed just one rehab appearance this time before joining the team, throwing nine pitches in a perfect inning of relief for Class A Advanced Stockton on Saturday.

He'll likely be eased back into his typical setup role.

"He's full-go, yet he's been off for a little bit and had the one rehab game, so we'll try to ease him back in," said manager Bob Melvin. "We won't stick him in the ninth with a one-run lead. Now, you say that, and he ends up coming in during an extra-inning game with the bases loaded or something like that, but the plan is to ease him in one time before we get him into a prominent role."

Cook allowed just one earned run in 9 1/3 innings over his first nine appearances this season before allowing three in his last three games leading up to the injury.

Moss returns to lineup, powers A's to win

NEW YORK -- Brandon Moss was back in the A's lineup Tuesday after missing a pair of games with a left calf strain, and he made an immediate and resounding impact.

Moss served as the club's designated hitter for the first contest of a three-game set in New York, while Alberto Callaspo got the nod at first base against Yankees righty Hiroki Kuroda. Moss clubbed a game-tying home run in the fifth inning and hit his second of the game and 15th of the season, a decisive solo shot, in the 10th inning of Oakland's 5-2 victory.

"I had been swinging the bat well tonight, so I knew they'd probably be careful, and it's just one of those at-bats you're battling, trying to get a good pitch to hit or get on base, and I ended up getting a hanging slider on a 3-2 count," said Moss. "Obviously any home run feels good, but in an extra-inning game, 2-2, it feels really good."

"He feels better today," said manager Bob Melvin before the win. "After being off a little bit, and as important as he is to us, we wanted to see how he reacts to some at-bats and actually getting out of the box, which is the most difficult thing with those types of injuries."

Moss, who recorded 19 extra-base hits in May to set an Oakland record, entered Tuesday a career .316 hitter against the Yankees.

A's place Reddick on DL with hyperextended knee

NEW YORK -- The A's were forced to place outfielder Josh Reddick on the 15-day disabled list Tuesday with a hyperextended right knee.

It's the first DL stint of the season for Reddick, who needed two of them last year because of ongoing wrist issues.

Reddick sustained the injury in Saturday's win over the Angels and is not expected to do any baseball activity until the A's return home next week.

The good news is there's no structural damage to the knee.

"But we're concerned about it to the point where he's not doing anything for 10 days," said manager Bob Melvin. "It's something we want to be careful with."

Reddick was batting just .214 with four home runs and 22 RBIs through 50 games with the A's, who added a left-handed bat Sunday to offset the loss of Reddick by recalling catcher Stephen Vogt from Triple-A Sacramento.

Craig Gentry got the start in right field in New York on Tuesday.

Jane Lee is a reporter for MLB.com. Read her blog, Major Lee-ague, and follow her on Twitter @JaneMLB. This story was not subject to the approval of Major League Baseball or its clubs.