SCOTTSDALE, Ariz. -- A little diversifying of one's pitching arsenal can go a long way in baseball, explaining Frankie Montas' satisfaction Monday with his two shutout innings in the A's 4-3 Cactus League loss to the D-backs.

Montas, a candidate for the fifth spot in Oakland's starting rotation, has added a split-finger fastball to his complement of pitches. The right-hander used it effectively against the D-backs, particularly when he struck out cleanup batter David Peralta to strand a runner at second base in the first inning.

"His breaking stuff's playing," A's manager Bob Melvin said of Montas, who'll turn 26 on March 21 yet is entering his 10th professional season. "He was a guy who relied primarily on his fastball."

Montas threw 20 of his 34 pitches for strikes, including five or six splitters by his own estimation. He figured that "adding something to my slider and two-seam fastball would help me."

This spring could be considered a critical one for Montas, who has no Minor League options remaining. If he doesn't begin the season with the A's, there's a good chance he would be picked up by another club if he pitches well.

"You hate to lose a guy that's as talented as him, so he'll get every opportunity to make this team," Melvin said.

"I wouldn't say it's an advantage," Montas said. "I would say that everyone here has to prove himself."

Montas proved his toughness when he pounced on a first-inning smash that Eduardo Escobar lined off his right hip. Ignoring the discomfort, Montas threw out Escobar at first base.

"See these big legs?" Montas said, jokingly explaining how he withstood the ball's impact.

Worth noting

• Despite the loss, the A's played some daring baseball. With nobody on and two outs in the third inning, Cliff Pennington bunted for a single on an 0-2 pitch, which set up Nick Martini 's RBI single. In the eighth inning, Franklin Barreto feinted long enough between first and second base to enable Luis Barrera to charge home from third.

• The possibility of operating with a three-man bench prompted a reporter to ask Melvin whether he ever played on teams that kept three catchers, which was common in previous eras. Melvin cited the 1992 Royals, which kept a trio of catchers through the entire season.

Up next

Melvin indicated that third baseman Matt Chapman might be fit enough to serve as designated hitter against the Angels on Tuesday. Chapman and Khris Davis were expected to take some swings in a simulated Minor League game on Monday. Mike Fiers will be on the mound for Oakland at 12:05 p.m. PT from Hohokam Stadium in Mesa, Ariz.