LOS ANGELES -- Newly acquired third baseman Chris Johnson got a crash course in the D-backs' signs from coach Matt Williams in the middle of the clubhouse on Monday afternoon.

It was just one of the many things that Johnson was working to get comfortable with after coming over from the Astros on Sunday.

"I have to keep my phone plugged in, because it's dying, people are calling all the time," said Johnson, who batted seventh and started at third base in the opener against the Dodgers. "A lot of new information I'm trying to process right now. Just trying to stay relaxed. It's the same game, but I'm excited to be here."

Johnson made a rapid rise in the standings. The Astros were 27 games out of first place in the National League Central, while the D-backs are just 4 1/2 games back of the Giants and Dodgers in the NL West.

"These guys have a good ballclub, a lot of guys in here that are proven players that I can learn from and a proven coaching staff I can learn from," Johnson said. "Since I was called up in Houston we haven't really been in contention over there, so this is my first time being in that sort of situation. I'm excited to go after it every night and try to make up some ground."

Johnson figures to get the bulk of the playing time at third base for now, but the D-backs will also try and work rookie Ryan Wheeler in there as well.

Overbay designated to make room for Johnson

LOS ANGELES -- Lyle Overbay did not need to say how much he will miss his D-backs teammates.

His tears said it all.

Overbay bid an emotional farewell to his now former mates Monday afternoon after being designated for assignment. The club has 10 days to trade, waive or release Overbay, who is hopeful of catching on with another club.

"I understand it," Overbay said. "They want to go young. It's part of the deal. Hopefully I've done everything that they've asked of me."

The 35-year-old Overbay was in his second stint with the D-backs. Originally drafted by the organization in the 18th round in 1999, he was traded away in 2004 before being brought back last August after being released by the Pirates. He served as a mentor for young first baseman Paul Goldschmidt.

"Great teammate," D-backs manager Kirk Gibson said of Overbay. "He's helped Goldy out tremendously. These things are never easy, but it was an organizational decision."

After a hot start to the season, Overbay had just two hits in his last 25 at-bats. With Sunday's acquisition of third baseman Chris Johnson, the D-backs had to essentially choose between Overbay and rookie Ryan Wheeler.

Wheeler's versatility -- he can play third and first, as well as the outfield -- worked in his favor.

"I was very lucky to have the opportunity to work with him," Goldschmidt said.

Towers working the phones as Deadline nears

LOS ANGELES -- D-backs GM Kevin Towers remained with his staff in his suite at the team's Pasadena hotel on Monday night, a white board detailing possible trade scenarios.

"We're just taking phone calls and looking at what our options are," Towers said.

The non-waiver Trade Deadline is 1 p.m. MST on Tuesday.

Since the D-backs acquired third baseman Chris Johnson on Sunday, speculation has intensified that they could deal shortstop and free-agent-to-be Stephen Drew.

Towers declined to answer when asked if he was getting a lot of calls on Drew.

"I really don't want to get into names and discussing actual names that we're talking about," Towers said. "All I would say is that we have currently [players] on our 25-man [roster] that people have asked about, as well as prospects, and we're looking at every other organization really with the purpose to improve our 2012 club if we can."

Drew had a closed-door meeting with manager Kirk Gibson on Monday afternoon, but both men said it was not a trade-related discussion.

Drew, meanwhile, continues to try and tune out the rumors.

"It wasn't no trade talk kind of stuff," he said of the meeting. "If something happens, it happens, then we'll know more about it. Other than that I'm still with Arizona and just going to prepare for tonight. We're still in the battle here."

As has become clear for a while now, it is unlikely that outfielder Justin Upton will get dealt before the Deadline.

"All I can tell you I have had no dialogue about Justin Upton today or yesterday," Towers said. "I think clubs have a pretty good feel that at this point in time we're 4 1/2 games out, and he's a big part of our ballclub. But I would say unless something drastically changes in the next 24 hours that Justin Upton is going to remain here."

Towers also reiterated that the club is not planning on dealing any of its top prospects -- such as Trevor Bauer or Tyler Skaggs -- and in most deals the D-backs are looking at getting back pitching.

"I think the roster as it is, is OK," Towers said. "But if we feel like we can improve it in other ways, we're certainly going to look at it."