Given that Downs spent the entire 2014 season in the majors I would expect this deal to give Downs the ability to opt out of the contract if he doesn't make the club. Hoynes notes that Downs would make a base salary of $800,000 if he did make the club, though given the current roster I don't think that's likely. Scrabble, Kyle Crockett, and Nick Hagadone all ended the season on the major-league roster, and would have the leg up on Downs before you even get to evaluating ability.
Latest 25-man/40-man roster
The main mystery that has been created by the Moss acquisition is how Terry Francona will manage at-bats between Moss, Swisher, and Murphy. Both Swisher and Moss are coming off surgeries, and presumably would not be very effective in the outfield, at least initially. Murphy is probably the defender of the three, but potentially the weakest bat. If nothing else happens to change this picture, then I would guess Murphy sits against all left-handed pitchers, and Swisher/Moss sit at least once a week.
With Floyd now in the rotation, that pushes TJ House to AAA. The Indians do have option left on Danny Salazar, so they could send him to AAA instead, but I think they'd want to save that option until they really need to use it. McAllister is the only "young" starter without an option, and I think he'll move to the bullpen. He has the stuff to be effective as a back-end reliever a la Wade Davis, and I'm concerned that the key pieces in last year's bullpen may not be as effective given the workload they shouldered in 2014.
Mystery Team has acquired yet another player. The Nexen Heroes of the Korean Baseball Organization (S. Korea's top-level baseball league) have accepted a posting bid from a major-league team for shortstop Jung-Ho Kang. Now whoever won bidding has to sign Kang to a contract, otherwise he'll return to the Heroes in 2015. Kang is just 27 years old, and had an outstanding season in Korea last year, hitting .356/.459/.739 with 36 doubles and 40(!) home runs. He was by several measures the best hitter in the KBO last season, although there's little history to figure out how those great numbers will translate to MLB. For reference, Eric Thames, a player who has played in MLB (96 OPS+), hit .343/.422/.688 in KBO a year ago.
Speaking of shortstops, LGFT Asdrubal Cabrera may be an option for the Phillies now that they've traded Jimmy Rollins.
And continuing the shortstop theme, the Angels have signed 21-year-old Cuban shortstop Roberto Baldoquin. He's not quite ready for the majors, so he'll start the 2015 campaign in AA.