Injuries have been the big story at D-backs camp during Spring Training, with the team losing three players who were expected to play big roles in 2021.

Starting right fielder Kole Calhoun was the first to go down when he had surgery on his right knee to repair a medial meniscus tear. He is expected to be ready not long after the season starts.

Right-hander Tyler Clippard, whom Arizona signed just after camp opened to be one of its primary setup men, sprained his right shoulder capsule and will be shut down for six weeks.

Then right-hander Zac Gallen, penciled in as the club's No. 2 starter, suffered a hairline fracture in his right forearm when he got jammed by a pitch during batting practice. The timetable is less certain with Gallen since the injury is somewhat unique, but he is not expected to miss as much time as he would have if there were muscle, ligament or tendon issues.

Best development
This is a tie between the performances of outfielder Tim Locastro and infielder Josh Rojas.

Locastro has swung the bat well during the spring. Between that and his ability to draw walks and -- somehow -- be a magnet for getting hit by pitches, he could be a serious on-base threat for Arizona. Once he's on base, his speed -- he had the best sprint speed in baseball in 2020 (30.7 feet per second), per Statcast -- allows him to be a stolen-base threat. He is 26-for-26 in career stolen-base attempts.

Rojas, meanwhile, changed his diet and workout regimen and made some mechanical adjustments at the plate over the offseason. The results have been encouraging this spring.

Locastro could be the answer to the hole in right field created by Calhoun's injury. Rojas could be the starter at second base the D-backs have been looking for, as well as Nick Ahmed's primary backup at shortstop.

Unfortunate events
Gallen's injury was a real blow to the D-backs. It's possible the right-hander will not miss a lot of the regular season. But given the way he has pitched since coming over from the Marlins at the 2019 Trade Deadline, any missed time hurts.

The good news is that the injury wasn't serious, as forearm issues often are.

"To me, that was the best news possible," D-backs manager Torey Lovullo said. "When we were considering what some of the other options are, obviously when you [are talking about] an elbow or shoulder and you’re a starting pitcher."

Player who opened eyes
After J.B. Bukauskas was acquired from the Astros in the Zack Greinke deal, there was some question whether his future was in the rotation or in the bullpen.

That hasn't been fully answered, but Bukauskas -- the D-backs' No. 17 prospect -- pitched in relief this spring and was dominant. In 5 2/3 Cactus League innings, the 24-year-old right-hander did not allow a baserunner while striking out 12.

Though Bukauskas was optioned to Triple-A Reno, he definitely made an impression.

Wow moment
Given his struggles last year, all eyes were on Madison Bumgarner when he took the mound for his first spring outing. The veteran left-hander did not disappoint as he struck out six of the seven batters he faced in his two-inning stint March 4 against the Angels. It set the tone for what has been a good spring for Bumgarner.

In case you missed it
Lovullo has some signature phrases that he uses throughout his sessions with the media. I put together a handy fan's guide to them.