OAKLAND -- A scorching July has turned the A's into surprising playoff contenders, which means they're now the type of team that could look to add another weapon or two before Tuesday's 1 p.m. PT Trade Deadline.

Oakland has been linked to several potential moves, in addition to the team's trade for catcher George Kottaras on Sunday.

But as A's manager Bob Melvin is keenly aware, with such a young team, the organization may not want to risk jeopardizing the team's future by giving away a young player in a trade that may not pay off.

"I think you look at every facet of it, how you improve your club, not only short-term but long-term," Melvin said. "You don't want to mortgage some of the things we have here with the younger players, and then, in turn, keep the guys and the pieces that are prominent in the clubhouse."

Another factor is chemistry. The A's seem to have one of the looser, more comfortable clubhouses in the Majors, and a disruption to that could be harmful.

Most rumors associate Oakland with looking to improve production at shortstop, with Arizona's Stephen Drew and Toronto's Yunel Escoabr the most prominent names. But Melvin has said in the past that he likes his team as is, and reiterated that on Monday with less than 24 hours before the deadline.

"If [general manager Billy Beane] feels like there's an upgrade out there, then certainly he'll pull the trigger on something like that, but we do feel like we have a good group here at this point," Melvin said.

A's welcome Kottaras, send down Norris

OAKLAND -- After the A's announced on Sunday that they acquired catcher George Kottaras from the Brewers, the team welcomed its new catcher to the Coliseum before Monday's series opener against the Rays.

To clear a spot for Kottaras on the roster, Oakland optioned rookie backstop Derek Norris to Triple-A Sacramento, ending speculation that veteran Kurt Suzuki, having a rough year offensively, could be traded.

Kottaras said he "kind of felt" Milwaukee would be making a move with him one way or the other given the way things were going. He received just 86 at-bats with the Brewers before they designated him for assignment on Thursday, leading to the trade.

As for the 29-year-old's playing time, the plan is to platoon the left-handed-hitting Kottaras with Suzuki, who bats right-handed. The A's now have a platoon situation at four different positions, the others being first base, shortstop and the designated hitter slot.

Kottaras goes from a backup role with a struggling team to regular playing time with a contender. Not a bad change, and he said he was "excited" about joining Oakland.

"Great attitude in here," Kottaras said. "You see guys having fun, but also getting their work in, which is the way it should be. [I'm] just trying not to step on anybody's toes. [I] just want to get to know everybody better."

Though A's manager Bob Melvin said he liked Kottaras' ability to get on base -- despite owning a .209 batting average, the catcher's on-base percentage is .409 -- he agreed with Kottaras in saying that the biggest immediate challenge would be for him to get to know the pitching staff, something Melvin himself had to deal with during his career as a Major League backstop.

To that end, Kottaras planned on playing catch with the pitchers to get to know their stuff, and was going to sit next to the coaches on the bench during Monday's game to try to absorb everything.

As for Norris, Melvin said the team wanted the rookie to get more regular playing time, which wouldn't happen with Suzuki also in Oakland.

Considering Norris was batting .195 overall after starting out with a .333 average in his first eight games, it wasn't necessarily a difficult choice to make. But Melvin reiterated that he's still a big part of the team's future.

Worth noting

• Outfielder Coco Crisp was out of the lineup again on Monday after injuring his left hamstring in Saturday's game against the Orioles. Melvin said Crisp wouldn't do any baseball activities for the second straight day, but would hopefully resume them on Tuesday.

• Shortstop Cliff Pennington, who began hitting off a tee on Saturday, did some soft toss and took some dry swings on Monday. For the first time, he didn't feel any pain in doing his activities. Melvin called it good progress for Pennington, who's been on the 15-day disabled list since July 20 with left elbow tendinitis. The manager also confirmed that Pennington will go on a rehab assignment before his eventual return.

• Right-hander Brandon McCarthy struggled on Monday night in his first rehab start since going on the 15-day DL on June 20 with recurring right shoulder soreness. Pitching in Reno for Triple-A Sacramento, McCarthy allowed seven hits and six runs in 3 2/3 innings. He threw 66 pitches, 42 for strikes.