The Mariners are still in the thick of the American League Wild Card hunt, and Alonso gives them a strong lefty bat who can provide production at first base. The M's entered this season hoping Dan Vogelbach might make the full-time leap to the majors, but he has been mostly stuck in the minors while right-swinging vet Danny Valencia has been holding down first base most of the season. Expect Alonso to get most starts at first moving forward.

This deal is a bit surprising, since there was significant chatter earlier this summer that the A's were interested in signing Alonso to an extension. Then again, his production has really dropped off in August after a great first half of the season, and the always budget-conscious A's save some money by moving Alonso's expiring contract. As a young and rebuilding team, Oakland can now spend the stretch run auditioning young prospects such as Matt Olson and Ryon Healy. Powell was originally drafted by Oakland in 2012 (Round 20), so he returns to a familiar organization.

Healy and Olson both get bumps up in fantasy value, since those two look likely to share at-bats at first base replacing Alonso for the A's. The fantasy news is not as good for Valencia, who now loses playing time at first base. Olson especially is worth a look as a pickup in keeper leagues; Powell is not as appealing, although he has shown some patience and speed in his pro career so far. Expect Powell to push for some outfield at-bats off Oakland's bench the rest of the way.