DETROIT -- The camera sat just over Casey Mize’s right shoulder, possibly the most important body part in the Tigers’ rebuilding effort, as Detroit’s top prospect threw in the indoor facility he has been using near his Nashville, Tenn., area home. He announced on Twitter a couple hours earlier that he would stream the bullpen session on Instagram.

Mize cranked up the velocity on his fastball for a stretch. He unleashed his trademark splitter and worked on his breaking ball. After each pitch, he checked the readings on spin efficiency and velocity, looking for his targets.

It looked a lot like a Spring Training bullpen session. Hours after he finished, Major League Baseball set plans in motion for its summer version of Spring Training next week, picking up where Mize, Tarik Skubal, Matt Manning and Alex Faedo left off in big league camp in March.

• Tigers FAQ: Details on the upcoming season

“These guys are going to be part of our 60 people in Spring Training,” Tigers manager Ron Gardenhire told reporters on Wednesday. “We want them working and they're going to get their work in, and then as we go along, they're going to continue to work, maybe on the Taxi Squad. This organization hasn't drafted these guys and brought them up to this point to all of a sudden say, 'You're not doing anything, just go ahead and go home.' No, they're going to be a part of it, with a lot of other guys. We'll keep them busy so that when we have an opportunity, we'll give them their shot. They deserve that. They're good pitchers.”

When MLB set up expanded rosters and Taxi Squads for this season, it gave teams a way to have reserves work out and be ready on short notice to fill spots in case of injury or other needs. The active roster will be expanded at the start, going from 30 players on Opening Day on 28 two weeks later, then to the standard 26-man roster two weeks after that. But the Taxi Squad also gives teams an opportunity to keep prospects working out and developing this summer with the Minor League season looking uncertain.

It’s up to individual teams to decide how to balance that mix.

“You have to have enough guys on the roster that you feel can get you through a season,” said general manager Al Avila, who has long preached the importance of pitching depth. “From an injury perspective, that's easy at this point. We have a history over the past five years how many total players we've used in a single season. I think last year we used the most, like 47 players total. That's [over] 162 games, but that's only when you're dealing with basic injuries, not the COVID-19 virus. Obviously you need more players because it's shorter preparation, and then you have the possibility of a breakout.”

At the same time, Avila said, “We are going to bring some prospects that we feel we'd like to continue to work with us and play some intersquad games until hopefully at some point this fall we can get them into a different situation in a different developing system.”

For advanced prospects like Mize, Manning, Skubal and Faedo, that decision is relatively easy. Before the pandemic delayed the season, they were expected to open at Triple-A Toledo. Now, they’re expected to be there as part of the Taxi Squad.

“There are some young guys that quite frankly if it was a regular season, we had plans at some point to bring them up and get them some experience,” Avila said. “A guy like Mize or Faedo would've been those possibilities. That would still remain the same as we move forward in this season. Those are things that we're still contemplating. There will be other guys that are younger that we're thinking about whether to add to this list or not.”

The trickier decisions come with prospects that aren’t as close to the Majors, who still have a year or more of development to go. Riley Greene made an impression as an extra player in Grapefruit League games earlier this year, but realistically is two years away from the big leagues. Same goes for second baseman Kody Clemens, who saw a good amount of work in big league camp.

“I can't fathom bringing up a guy who played A-ball and having him play at the Major League level in a 60-game schedule,” Avila said. “For me, that wouldn't work. I would say that depending on the final decisions that we make between now and Sunday, there will be probably some guys that yes, we would probably use at some point if necessary, and there will be guys that we definitely wouldn't. But that depends on who's going to make the final cut on the 60-man.”

Then there are the Tigers’ highly regarded picks from this month’s MLB Draft, led by top selection Spencer Torkelson. All are position players. All but one of them played college ball. All had their spring seasons halted by the pandemic.

Avila said he already has a 60-man roster list ready, barring last-minute changes. The Tigers' decision Thursday to release veteran reliever Alex Wilson is a hint how that list might look. Wilson was in Spring Training as a non-roster invite battling for a bullpen spot, but the Tigers decided that he wouldn’t make the list.