Smith batted .284 in 147 games for the Rockies last season, with 15 home runs, 59 RBI and 10 stolen bases.
The 6'3" 210-pound left-handed hitter batted .299 with 14 home runs and 47 RBI last season vs. right-handers, but just .217 with one home run and 12 RBI vs. lefties.
Moscoso posted an 8-10 record with a 3.38 ERA in 23 games for the A's a season ago.
He ranked second among AL rookies in ERA, third in opponents BA, fifth in wins, sixth in both games started and innings pitched, and tied for eighth in strikeouts.
The 28 year-old also set an Oakland record by retiring 30 consecutive batters over two starts on Sept. 2 and Sept. 7.
Outman missed the entire 2010 season following Tommy John surgery in June 2009, but returned in 2011 and recorded a 3-5 record with a 3.70 ERA in 13 games for the A's.