Two of Rivera's strikeouts were looking during a perfect sixth. He threw nine of 12 pitches for strikes.
Rivera has taken a slower approach in recent years at spring training. Rivera was 3-3 with a 1.80 ERA and 33 saves in 38 chances last season. The 11-time All-Star has 559 regular-season saves, second to Trevor Hoffman's 601, and a record 42 in the postseason.
Baker, bidding for a spot in the Minnesota rotation, allowed one run and two hits over four innings.