MESA, Ariz. -- Arizona Diamondbacks starting pitcher Zac Gallen is being evaluated for soreness in his right forearm and might not be ready for the start of the regular season on April 1.

The 25-year-old Gallen said he first felt the injury when he was jammed during batting practice about 10 days ago. He said he can feel it when he throws his curveball.

Gallen, who was scratched from his scheduled start on Monday, said he got an MRI and an X-ray on Sunday and doctors were still evaluating the results. He said he still felt good physically and hopes this is just a minor setback.

"We're still gathering information, so it's tough to really map out a plan," Gallen said. "For me, though, mentally I'm going to want to be on the field as soon as possible. I'm going to be chomping at the bit."

Gallen was Arizona's best pitcher last season, finishing with a 3-2 record, 2.75 ERA and 82 strikeouts in 72 innings of work. He was ninth in the NL Cy Young Award voting.

Gallen said on Monday it was frustrating to get hurt while swinging the bat instead of throwing on the mound. The right-hander is in favor of the designated hitter in both leagues, which was the rule across Major League Baseball in 2020 in the shortened 60-game season.

The NL switched back to pitchers hitting for the 2021 season. Gallen said he understands hitting is part of the job in the NL but it's frustrating when he gets pinch-hit for in the middle innings of games.

"It's definitely frustrating considering I'm kind of an advocate for the DH," Gallen said. "I get paid to pitch, that's kind of how I look at it. It comes along with the job. I play in the National League, you have to hit, you have to bunt, you have to do those certain things."

The Diamondbacks have had multiple injuries to key players during this year's spring training. Starting right fielder Kole Calhoun had knee surgery earlier this month and is expected to miss at least the first few weeks of the season. Right-handed reliever Tyler Clippard is battling shoulder soreness and has been shut down from throwing for at least six weeks.

Lovullo said he didn't want to speculate on who could take Gallen's rotation spot if he isn't ready for the regular season. Likely candidates include Alex Young, Taylor Widener or Taylor Clarke.

"We're in good shape," Lovullo said. "If we have to pivot, we're in a good spot. We're going to have a lot of guys who are stretched out and ready."