Justin Ruggiano - Ruggiano has started five of the last six games for the Rays (and has hit in all of them), as Tampa continues to find productive spare parts to remain firmly in contention. Ruggiano's persistent issues with contact are really all that's prevented him from being a bonafide top prospect on his way up the ladder, as he certainly possesses a reasonable power/speed combo and is capable of playing all three OF positions. Ruggiano's ceiling would probably be that of a 15/25 guy, but to discover that sort of performance from a AAA lifer at age 29 isn't bad at all. For the time being, it looks like Ruggiano will not get to add to his roughly 1750 AB's at Durham, but will instead be starting much of the time for the Rays, and is thus a worthwhile pickup (and start) in all but the most shallow of formats. Expected AVG decline is the only negative that I see here.
Jemile Weeks - Injury interceded where design would not, and with Mark Ellis on the shelf with a strained hammy, Jemile Weeks is getting a chance to try and handle the starting 2B job in Oakland. The 24 year old Weeks is a guy that's best skill is probably his plate discipline....the rest of his skill set probably grades out around average to above (his defense is likely slightly below) without one standout area. With the weakness of the 2B position right now, Weeks is an immediate start in AL-only leagues and likely in many mixed leagues as well, with the possibility of a 280/360/430 type line with 10-15 homers and 15-20 steals.
Brent Lillibridge - Lillibridge has been picking up quite a bit of playing time lately, much of it at the expense of Juan Pierre. He's likely already eligible at 2B and OF in your league, and although the power and AVG aren't likely to last at these levels he does have enough pop (and speed, of course) to be useful in most formats, particularly those that value OBP. I expect that he'll continue to play more than 50% of the time, and that he'll contribute enough across the board to be a worthwhile add in all AL-only formats and some deeper mixed leagues as well.
Carlos Peguero - Carlos Peguero is part of a sudden youth movement in Seattle, and the hulking 24 year old has the massive power of the prototypical right fielder. He already has five homers in his first 83 AB's, but as far as the rest of his game.....his swinging strike% is almost 20. Contact issues are going to plague him consistently, so it's unlikely that he'll ever be much more than a one (or two, if the M's offense improves) category guy. He's an AL-only start right now, with the potential to be a solid mixed league starting OF at his best.
Greg Halman - Halman is another part of the Mariners youth movement, as the 23 year old has also been playing most of the time this week as the M's continue to break in young players across the diamond. Halman is a right-handed version of Carlos Peguero, albeit with much more speed but potentially even greater contact issues. Halman has clear 20/20 potential (he was one homer away from 30/30 across two levels in 2008), but the AVG and OBP will be perpetual problems. For now, much like Peguero, he remains an AL-only option at best, but the potential is there for more in the future. His ceiling is even higher than Peguero's.
Cord Phelps - The Indians have finally tired of the complete calcification of "the real O.C.", and have called up Cord Phelps to be the primary 2B. Phelps is only 1-11 through his first three games, but the 24 year old has shown a smidgeon of power growth since midway through last season, enough so that you could perhaps picture him as something like a 270/340/420 bat going forward. He doesn't have much speed, and I doubt he'll ever hit more than 10-15 homers, but his contact ability seems strong enough to justify a spot in AL-only leagues right off the bat.