Mets manager Luis Rojas during a spring training workout on...

Mets manager Luis Rojas during a spring training workout on Feb. 12, 2020 at Clover Park in Port St. Lucie, Florida. Credit: Newsday/Alejandra Villa Loarca

As the Mets prepare to enter baseball’s brave new world Friday, when they hold their first official workout of a restarted preseason camp at Citi Field, manager Luis Rojas quickly learned that playing during a pandemic is going to be difficult.

Already, the Mets have had one player on the 40-man roster test positive for COVID-19, general manager Brodie Van Wagenen revealed this week. Rojas said hitting coach Chili Davis, who is 60 and lives in Arizona, a recent coronavirus hotspot, will not be with the club for at least the start of camp because of  health concerns. And the team will learn ahead of their Friday morning gathering if any other players or staff tested positive and thus need to be held out.

If and when a player does contract the virus, the Mets estimate it will take about three weeks until he is back to normal baseball activity — and that is a best-case scenario with an asymptomatic result.

"It could take probably a third of the season if you lose a player — according to our calculations, just to get the player back and ramped up,” Rojas said during a video conference with reporters Thursday afternoon. “The whole process, which I’m not going to get into detail, is going to take us maybe a three-week period until the players ramp up back into activity. That's basically what we discussed. We've talked about us having depth and maybe somebody coming in and filling the spot for a time, but it can definitely turn out into a competitive [dis]advantage.”

Assistant hitting coach Tom Slater will fill in for Davis, who will contribute to the Mets remotely, Rojas said. And minor-league hitting coordinator Ryan Ellis is joining the big-league club to assist Slater.

The rest of the Mets’ coaches are on board for 2020.

Did Rojas have any reservations about managing this year?

“Not really,” he said. “I’m really excited right now. I’m excited to get into this.”

Rojas stressed two themes of the Mets’ coming days and weeks: communication and education. There are all sorts of new health and safety protocols everyone will need to learn and follow — social distancing measures, no high-fiving or spitting, testing every other day — and players and others will need to be smart away from the ballpark, too.

With camp constrained to just Citi Field, as opposed to the half-dozen or so fields the Mets would have had at their disposal at their normal spring training facility in Port St. Lucie, , they need to get creative. They will start with three sessions of workouts, which will feature live batting practice/simulated game situations so players can readjust to the appropriate intensity.

“I grew a few more grey hairs just brainstorming through this,” Rojas said of the logistics.

Rojas and the Mets only have so much time in the day to communicate and educate, though. Infectious disease-related considerations compete with baseball planning and strategy for that finite bandwidth.

“We’re all probably experts in Zoom calls right now at this point,” Rojas said. “So we had all those Zoom calls where we talked about strategy and we had Zoom calls where we talked about logistics — how we’re going to behave with this. We’re covering it all so we can educate the players, so we can educate ourselves and navigate through this and, at the same time, be able to focus on our baseball.”

Rojas said the toughest part will come early as players and staff adjust to new routines. Then the baseball side will come easier.

“Once they get educated and they know, they get into a routine and how to move around, I know that that baseball focus we need in order to keep preparing for the season is going to take over,” Rojas said. “We are going to be strict from the start, but I know … we're going to be able to prepare just the same and have fun out there and bring baseball to the fans.”