A's director of player development Keith Lieppman is celebrating his 41st season with the organization and 20th in his current role, one which takes him all around the country as he keeps a close watch on all happenings within Oakland's farm system.

Having just taken in a Class A Burlington Bees game in the Midwest, Lieppman recently took time out of his constantly busy schedule -- which has him at one or two games on nearly every day of the year -- to chat with MLB.com about some of the club's top prospects.

MLB.com: How are Michael Taylor (wrist) and Chris Carter (thumb) coming along in their respective rehab programs?

Lieppman: Michael is the closest to coming back. He was just cleared by our hand specialist [Thursday], given the OK that he's 100 percent ready to go. Now we just have to get him enough at-bats down in Arizona to where he can rejoin the Triple-A club in Sacramento. The thinking is that it shouldn't be too long on him.

Chris is still with Sacramento, doing rehab in the thumb area, looking for mobility and just trying to get it to where it has some flexibility and doesn't hurt. It's a weird part in his thumb, but such an important part of swinging the bat and catching the ball. It's the same thumb he injured last year, and, unfortunately, it's taken longer than expected.

MLB.com: What kind of progress did you see from them in big league camp this year?

Lieppman: Michael had a good Spring Training, and Chris held his own. I thought they both did very well. The configuration of the club, with Josh Willingham and Coco Crisp and others, there just wasn't a place for them to get everyday at-bats. I think the feeling of the organization was that it would be best for them to continue to progress at Triple-A and then see how things go from there. I think they're doing great, actually, aside from the injuries, though.

MLB.com: Playing in the outfield has been a big adjustment for Carter. How much of that has slowed him in his journey to becoming a big league mainstay?

Lieppman: I think that had a little bit to do with his slow start through the season hitting-wise last year. When you're trying to focus on a position that you're uncomfortable with, it takes a lot of focus away from your at-bats. There came a point toward the end where we felt like, if this is going to be a distraction, there was some thought of letting him go back to first base to regain his confidence with the bat, because he certainly is a force when he feels good at the plate.

That may be the most important factor in his progression right now -- when he comes back, there may not be that quick push to put him in left field. We want him to regain confidence, so if that means putting him at first base and making it more of an experiment to play the outfield during winter ball, that would be the case. That power and his ability is going to show up.

You just never know when players are going to put it all together, mentally and physically. When they're talented, like both Carter and Taylor are, once they do, those are the kind of guys that are great players, everyday players in the big leagues. There's no perfect time, you can't predict when it all will happen, but they'll be fun to watch.

MLB.com: Who are some of the other key prospects dealing with health issues at the moment?

Lieppman: At one point, Andrew Carignan was kind of on the fast track for us, and he suffered a ribcage pull last year that took him down for awhile. He also had an elbow problem. He's working now, getting everything back together, in extended spring, and we're hoping he turns a corner here pretty soon.

Michael Ynoa is also working really hard in Arizona and continues to make progress. He's in a throwing program and working himself up to a mound progression. Eventually, mid-summer, we're hoping he'll be ready to pitch in the Arizona Summer League. If everything goes well, he would progress up through the system from there.

MLB.com: How about Sean Doolittle? Is he on his way back to Sacramento's roster soon?

Lieppman: He was doing great. He was about a week away from being sent back out to Sacramento. Just two days ago, for some reason, he took a swing and he felt pain in his wrist. So he's having some diagnostic tests done on his wrist right now to figure out what's going on. It may be another situation where we have to wait and see how he responds. His knee had healed completely, and all of a sudden this showed up. I feel sorry for him. The frustration that he's experiencing, it's just been a lot of bad luck. I think we're all pulling for him -- that's the sentiment of all the organization, that this guy is working hard and been through numerable rehabs and yet still is not out there.

MLB.com: We're usually used to pairing Jemile Weeks with some kind of injury also, but he looks to be performing well. What have you thought of him so far?

Lieppman: He's been outstanding. I've really enjoyed watching him. He had a collision at home plate where he tweaked his hamstring, but other than that, we're seeing a complete player, with the speed and occasional power, excellent on defense, just really evolving. We never got to see him at 100 percent because of his injuries, so now we know what the scouts saw when he was a No. 1 pick. His production right now, it's everything you want out of a player. He's making his way and making a statement right now, and we're all noticing it.

MLB.com: How close do you see him being to Major League-ready?

Lieppman: He should be in the mix within the year. I'm not sure he's ready to be called up right now, but given the fact this is a kid who hasn't had many Minor League at-bats and hasn't really had a full season, you let him play and see what happens, hope injury isn't a factor. The way things are going right now, on a natural progression, he's a guy you start looking at toward the end of the season.

MLB.com: Along with Weeks, 2010 first-round Draft pick Michael Choice impressed many in camp this year. How is he doing?

Lieppman: I just saw him in San Bernardino. He's having to adjust quickly to the Cal League, having played a limited time last year. He's holding his own. He's a target. They know that this guy's good, and this is his first real trial. Mentally, he's handling it great. He's just working on some mechanical issues and learning how to be an everyday player. But he's doing great on defense, throwing well, and at the same time we're seeing the speed and the power. It's pretty exciting to see him but, like everyone else, he's going to scuffle a little bit, gain some confidence and get better as the season goes on.

What's great about Michael is that he understands the big picture of things that will enable him to be a great professional player. Results aren't part of that program right now. It's all about approach. You recognize that the foundation your building is something you want to hold up over time and against good pitching. They have to have an approach that will sustain itself against someone like King Felix.

MLB.com: Upon Trystan Magnuson's promotion on Wednesday, several questions were asked about Joey Devine's status and whether he's close to rejoining the A's bullpen. Is he back to complete form?

Lieppman: He's been outstanding. I think he's definitely in a position to go to the big leagues. I think everyone who has seen him has noticed that his command is better and his slider is back. I think you want to give him as much opportunity to repeat it, just to make sure it's all together for him. Each time out, he's gaining confidence. He looks real good, so I can't imagine he'll spend much time in the Minor Leagues. He's opening a lot of eyes, and he's certainly not going unnoticed.

MLB.com: Devine and Josh Outman were essentially on the same rehab schedule for most of last year and showed signs of their old selves in camp. How has Outman looked?

Lieppman: He's at the point in his rehab where he's really just getting the rust off of it all. He had a great outing Wednesday, and each one has progressively gotten better. It took him a little longer to get his command and his feel back, but the velocity is there, the breaking ball is good. Sometimes guys get off the radar for a bit, but in the back of our minds, we knew that he's there, and you're starting to see some of the finer points of his game come out.