Despite all the home runs last season, Carter managed to only hit .258 at triple-A with a 30-percent strikeout rate. He hit three home runs in 70 major league at-bats late in the season with the A's, but he also struck out 21 times and hit only .186. His contact rate was a mere 67 percent. In his 105 triple-A plate appearances this season, Carter struck out 31 times (36.5 percent strikeout rate). There is some risk that he becomes just another Chris Davis.
The other problem is playing time. Mark Ellis, fresh off the DL, got the start at first base today with Jemile Weeks remaining the starting second baseman. The A's would love to build a little trade value in Ellis and letting him prove that he's healthy is the only way to do that. Daric Barton has been optioned to triple-A, so Carter could see some time at first if Ellis ends up splitting time between second and first. Conor Jackson started in left field today, but has also spent time at first base. Carter can play left field as well, so we could see this trio of players getting moved around a bit.
Deep leagues looking for some power upside can consider Carter, but I don't expect him to do much in the AVG department. Maybe he'd have a little more value in OBP leagues, as he knows hoe to take a walk. The bottom line is that, while the power potential is huge, the risk for too many strikeout and not enough AVG/OBP will probably counter that upside.