During the winter, Keith Lieppman was at the head of restocking Oakland's depleted farm system. The A's director of player development directed his focus to general manager Billy Beane's master plan of rebuilding with youth and, by Opening Day, he had deemed the replenishing effort a success.

With the second half of the season now in full bloom, Lieppman took time to offer MLB.com a midseason report on the A's farm system and how the team's goals have panned out. In his 17th season as the organization's go-to guy for the assignment, development and evaluation of Oakland prospects, he spoke from Vancouver -- where he was in the middle of a five-day trip assessing the A's Class A Canadians.

By the start of the season, you had basically filled every spot available in the A's farm system. Now that you've been able to watch the results of your offseason work, how would you assess the organization's progress?

Lieppman: It's been outstanding. We've acquired some outstanding young prospects. Every trade we've had, we've picked out two or three of the best prospects, and adding those guys to the already existing prospects we have in our system is an exciting time -- not only for the organization, but the teams that they play on.

I know our managers are excited every time Billy makes another trade. We're getting great players that are helping our teams. Having these quality players also creates a lot of competition, and competition for at-bats with existing guys. So I think we're seeing the level of intensity pique up a bit.

Guys are really trying hard because they want to get those at-bats. With the addition of the players, there's a sub-situation going on where guys are really wanting to play hard and try to impress so they can move to the next level.

Would you say that competitive atmosphere is found more so with the A's Minor League teams when comparing them to other organizations?

Lieppman: Yes, I do think so. Right now, it's a situation, with the influx of so many players. All of a sudden we're having to make harder decisions on who gets to play and how many days a week.

That, ultimately, is the hardest part of the Minor League system. You got 25-man rosters and you want to make sure guys are getting playing time, and now the decisions are becoming more difficult -- especially when you're getting such good players -- but you can only play nine at a time. It's a situation where some guys have to sit on the bench, and they're not generally used to doing that.

Taking you back to the winter, 13 of those new guys came from trades. Several, such as Greg Smith, Dana Eveland and Carlos Gonzalez, are already excelling in Oakland. Who do you think A's fans will be seeing next out of that group?

Lieppman: You look at Aaron Cunningham, who was in the [Dan] Haren trade, who's at Double-A Midland right now hitting about .305. He runs well, he throws well and he certainly has put himself in a position to be looked at.

In Texas, people think it's a real hitter's league, but it's not as easy a hitter's league as it used to be. Ballparks have changed and, to hit what he's hitting right now, he's certainly off to a great start after being injured early. He's certainly someone we're all looking at as a potential guy in the next couple years.

Also in that deal, Brett Anderson has certainly been outstanding. A lot of people rave about him, and I've talked to a lot of different scouts and player personnel people. And, whenever you see him, he may be a quick-move guy too -- maybe as quickly as Eveland or Smith got to Oakland. He's got a great arm and knows how to pitch, so I think we can look at him as somebody who, after the Olympic Games are over, might be in the mix.

When taking a look at players who have come up through the A's farm system, many wonder why Travis Buck is back at Triple-A Sacramento. He was expected to be a key component in Oakland this year, so what do you see going on with him?

Lieppman: It's just been a weird year for him, starting even from the very beginning when there were all of the expectations. He put a lot of pressure on himself to be a team leader, tried to do a little too much -- and combined with injuries, it really left this as an odd year for him.

I think everybody still has great hopes for him. And what we saw last year, I think he'll rediscover that. It's just that every fluky thing has gone wrong with him, from minor injuries to a tough start early in the season, where he went 0-for-20-something. If he had done that in May or June nobody would have ever noticed it, but right out of the chute it kind of put him behind.

He's good talent, and is just going to use this as a learning experience and will be fine.

You mentioned Buck's minor injuries. There have certainly been a number of minor and major injuries in Oakland this year, but have you seen many significant injuries to key players in the team's farm system?

Lieppman: We lost Fautino De Los Santos, the kid we got in the White Sox trade. He was at Stockton and he injured his elbow at the end of May. He was doing great, was one of our top kids and had been the No. 2 prospect with the White Sox. That was one of the major injuries in the farm system, and that's been a frustration for all of us and him because he was off to a great start as a pitcher.

A lot of these big names often overshadow some guys who get shuffled around in the Minors. In your opinion, who would you consider somewhat of a diamond in the rough?

Lieppman: Some unexpected good stuff happening is with Cliff Pennington, an infielder at Triple-A that had started the year at Double-A. He's a former No. 1 pick that has been limited because of injuries and really hadn't produced a whole lot. He's had pretty much a career year and impressed a lot of people, so he's made a lot of progress and put himself in a position to be looked at down the road here.

Have you had the chance to make much of the A's top draft picks this year?

Lieppman: Right now, Jemile Weeks is really doing great at Kane County. He started off a little slow, but there's always a little bit of an adjustment to the wood bat. But he made that adjustment pretty quickly. He's hitting about .330 right now, and to go right out of college baseball to Low A is not an easy jump.

Tyson Ross -- a top pick -- has been limited just because of injuries. We haven't had much of an opportunity to assess him. He's basically on a rehab to make sure he's healthy.

Another top pick, [Petey] Paramore, has had a quad injury and has just now gone to Kane County, so we should start seeing some good things out of him in the next four or five days.

Who do you expect to get the call to Oakland come September when rosters expand?

Lieppman: Eric Patterson, who we got from the Cubs for Rich Harden, has gotten off to a great start at Sacramento. He's shown some power, played really good second base and has impressed everyone who's seen him so far. I think a lot of people are excited about our acquisition with him, so he's certainly a guy that would be considered.

Cunningham is another guy. Also worth mentioning, Gio Gonzalez is really ahead of all the other guys. He's probably the guy closest to going to the big leagues right now.

How do you keep track of all these guys?

Leippman:[Laughing] It's keeping me busy, I tell you. Especially when Billy makes his trades, I gotta relearn all these new guys every three or four weeks.