Saunders was on Orioles executive vice president Dan Duquette's wish list this season -- he signed a one-year, $6 million deal with the Diamondbacks after being non-tendered -- and Duquette had been in discussions about Saunders with Arizona for weeks before consummating a trade this weekend.
So what does it mean?
Saunders, 31, gives the Orioles starting rotation the veteran presence it needs and has been lacking over the past six weeks with the absence of right-hander Jason Hammel. No member of the existing starting rotation has more than 13 career wins (Chris Tillman and Zach Britton). Rookie Wei-Yin Chen has 12 wins. So Saunders immediately becomes the Orioles' winningest pitcher (75-62 with a 4.17 ERA in eight seasons).
In his past stops in Anaheim and Arizona, he's been a middle-rotation starter. In Baltimore, he will be seen as an anchor of a young pitching staff.
A former first-round pick of the Angels in 2002, Saunders entered this season having pitched at least 186 innings in each of the past five major league seasons, including three straight 200-inning seasons from 2009-2011.
Saunders brings a resume of late-season and postseason success. He's 16-9 with a 3.98 ERA in 35 career starts in September and October. He's also made four career postseason starts. No other Orioles starter has made more than one (Hammel).
But more than anything, Saunders gives the Orioles a third left-handed starter, joining Chen and Britton. He's held left-handed hitters to a .207 batting average over his career.
That track record of success will be valuable against left-handed heavy lineups -- particularly the Yankees and Rays, both of whom are ahead of the Orioles in the standings.