ST. PETERSBURG — There’s a lot even top Rays officials don’t know about how their players are going to look, perform, react — and, most importantly, feel physically — as they gather this week for the start of summer training camp.What they do know is who the 60 players are they will pick from to set a 30-man, season-opening roster and the eventual replacements for injuries and infections.Here are three things we think we know about that group and how the Rays will plan to use it while operating within some changed rules and restrictions.Almost every decision the Rays make in setting their roster will be based on making the best use — and taking the best care — of their pitchers, specifically those starting or working bulk innings.With the pitchers coming off an extended 2019 season, starting to build up for the season in February and early March, being shut down to some degree for nearly 3½ months and now preparing again on an abbreviated training schedule, the Rays are going to be understandably cautious — especially early — with how often and how much they pitch. (Plus, Blake Snell and Tyler Glasnow missed extended time in 2019 with injuries, and Charlie Morton worked career-high innings.)Does that mean going to a six-man rotation? Planning for tandem starts, with two pitchers slated for three innings each? Using the opener strategy more? Or, in preserving bullpen innings, less?Those answers will determine how many spots on the 30-man, opening-day roster they need for pitchers — 15? 18? The result will then dictate how much room they have for extras, such as a third catcher, or a speedster to use in extra-inning games as the runner on second.“There’s a lot of things we’re going to need to look into,‘' general manager Erik Neander said. “We don’t want to get too far ahead of anything without first seeing how our pitching, their status through camp, their progression from a workload standpoint, what they can take on, and ensuring that we’re not putting too much on them too soon. Their health, their well-being and being responsible for the pitching side of things as they build up is going to be really important and have a big say in how they shape this thing.‘'The Rays will reconvene at Tropicana Field with the same group of catchers they had in mid-March, which could be good and bad. Mike Zunino is the starter, lefty-hitting Michael Perez the leading choice to be the No. 2, with non-roster veterans Kevan Smith and Chris Herrmann in the mix.Zunino is coming off a miserable offensive year but is confident some small changes to his swing will make a big difference. Perez has missed time with injuries both of his seasons in the majors.Smith has some defensive issues but can add offense, though he is right-handed, like Zunino. Herrmann hits left-handed and can play outfield but is 32 and hasn’t played a full season since 2017, due to injuries.“It’s a position where it’s always good to have options, especially how this season is being structured, the 60 games and really needing to be dependent on the guys you have in your own camp,‘' Neander said. “To have as many options as we do to get through this, I think it’s going to really play to our benefit.‘'Otherwise, the Rays seem to have everything else covered except a right-handed-hitting first baseman, where they will have to count on Jose Martinez improving his defense to be comfortable.The 60-man player pool is pretty much what a team has to work with, as Neander said, but not finite. Additions, including trades, can still be made, or call-ups from players in the system who are still sitting at home. But the players being replaced on the 60-player list — unless they are on the COVID-19 or 45-day injured lists — can’t rejoin the pool. So if the Rays release or waive one player to add another, they can’t bring the first one back at any point. While some teams kept spots open for additions, the Rays went with a full 60, though they could have a couple they could jettison without much impact on their overall talent.Also of note, only players on the 60-man lists can be traded, so that will limit deals involving prospects. And, players still have to be placed on the 40-man roster to join the active roster (though not the three-player, one being a catcher, taxi squad allowed for road games). So if the Rays want to use lefty Aaron Loup, one of the veteran catchers or any of the other 21 non-roster players in games, they have to first make room on the 40-man roster, which is pretty stacked. Putting injured Brent Honeywell on the 45-day injured list is a way to get one spot, though he’d get major-league service time.* Bill Evers, the 23-year Rays staffer who joined the Twins big-league coaching staff last year, won’t be allowed to work games this season due to his age, 66, and health history given the COVID-19 threat, the Minneapolis Star-Tribune reported. Evers will remain on the payroll and may serve in an advisory capacity.* Field coordinator Michael Johns and pitching development director Dewey Robinson will run the Port Charlotte camp with help from Triple-A pitching coach Rick Knapp and other members of the minor-league staff.* The Rays on Monday started the camp-opening testing protocol for players, with plans to have all tested by Wednesday and start workouts on Friday for the 37-player squad at Tropicana Field, working in shifts of small groups. Workouts for the 23 players in Port Charlotte may not start until Saturday.