Mahon was with the Diamondbacks for Saturday's 4-1 loss to the Cubs, and he got into the action because of starter Micah Owings' struggles. Coming in with runners on the corners and two outs, Mahon struck out Geovany Soto to end the inning.
Mahon, 24, was a combined 6-5 with 21 saves and a 1.62 ERA at Class A South Bend and Visalia and Double-A Mobile. He walked 11 and struck out 41 in 66 2/3 innings -- two more frames than he threw in his entire college career.
Mahon spent five seasons at Minnesota, including a redshirt year, but appeared in only 29 games, going 3-3 with a 7.10 ERA. He then went undrafted, but the Diamondbacks signed him as a free agent in 2006, and Mahon has enjoyed quick success in the Minors because he throws a sinking fastball in the range of 90-96 mph.
Evidence of the pitch's heavy nature can be found in Mahon's home run rate. He allowed only three long balls in his college career, and after yielding four in 36 innings with Class A Yakima in 2006, Mahon allowed only two last year.
Slaten healing: Lefty specialist Doug Slaten is coming along well in his return from microfracture surgery on his right knee. He threw a bullpen Friday and, according to manager Bob Melvin, has his arm in good shape.
"As a matter of fact, based on what he's doing on the mound now, he could probably pitch in a game, but because of the knee, he hasn't done any PFP [pitchers' fielding practice] or things like that," Melvin said.
Something new: Spring Training is a time for clubs to try out all their various plays, even if they have an adverse effect on some exhibition innings.
That might explain why the Diamondbacks went for the rare sacrifice popup Saturday after Augie Ojeda's one-out triple. Justin Upton popped up to second just beyond the dirt in short right field, and Ojeda took off for home. Mike Fontenot's throw beat Ojeda home by several lengths.
Melvin said that it looked like Fontenot might have had to catch the ball with his back turned to the infield, and had that ended up being the case, Ojeda might have had a better chance to score.
"In Spring Training, you want to work on those things," he said.
Bonifacio backs up: Emilio Bonifacio is no longer just a second baseman. He slid into the lineup at left field Saturday and batted leadoff.
Bonifacio, 22, played outfield in winter ball, and Arizona was understandably enthused about him expanding his defensive abilities.
"It just gives him other options for us," Melvin said.
Montero moving along: Catcher Miguel Montero will do light physical activity and then get another CT scan on his fractured right index finger late next week. His timetable remains uncertain, but it seems unlikely that he will be ready for Opening Day.
Up next: Split-squad action will divide Seattle Sunday, and the Diamondbacks will try to conquer a Mariners faction headed by left-hander Horacio Ramirez at Tucson Electric Park at 1:05 p.m. MT. Brandon Webb will open for Arizona.
Mark Thoma is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.