WASHINGTON (AP) — Baseball’s two World Series finalists canceled workouts Monday because of COVID-19 testing delays that one executive worried could endanger the baseball season.

The defending champion Washington Nationals and reigning American League champion Houston Astros each called off training camp practices after not receiving test results from Friday.

The cancellations come amid delays around Major League Baseball, with some players opting out, and in the aftermath of Nationals reliever Sean Doolittle criticizing slow test results and a lack of some personal protective equipment.

“We will not sacrifice the health and safety of our players, staff, and their families,” Washington general manager Mike Rizzo said. “Without accurate and timely testing, it is simply not safe for us to continue with summer camp.

“Major League Baseball needs to work quickly to resolve issues with their process and their lab. Otherwise, summer camp and the 2020 season are at risk.”

Astros general manager James Click said the delay in testing results and the contagious nature of the coronavirus led to the decision to cancel a full day of workouts.

“Despite these delays over the holiday weekend, we’re optimistic that this process will be ironed out and we’ll be back on the field and ready to compete for a championship soon,” Click said.

Atlanta Braves outfielder Nick Markakis on Monday became the latest high-profile player to choose not to play this season.

Los Angeles Dodgers pitcher David Price, Colorado Rockies infielder Ian Desmond, Nationals first baseman Ryan Zimmerman and Braves pitcher Félix Hernández are among those who have opted out.

Two Nationals players were among the 31 to test positive during intake testing last week. Manager Dave Martinez said Sunday some of the 60 Nationals players tested were still awaiting results.

“Obviously, this is all new for everybody,” Martinez said. “We’ve hit some bumpy roads. But they’re doing the best they can. I know they are. They’re working on cleaning everything up. We’re in a very, very different situation. No one’s ever done this before. So I know they’re working out all the bugs.”

Doolittle, who is still on the fence about playing this season, said he still hadn’t gotten his Friday results back before being tested again Sunday.

“That’s one thing that makes me a little nervous,” Doolittle said. ”We’re not getting tests back in time. They still haven’t sent us the PPE. We’re supposed to have N-95 masks, stuff like that, gowns, gloves.

“We’re supposed to have that stuff, we don’t have that stuff. Those are the things it’s going to take for people to stay safe enough for us to continue this season.”

In Oakland, two projected members of the Athletics’ starting rotation, Mike Fiers and Jesus Luzardo, missed their second consecutive workout Sunday because of what manager Bob Melvin called a “pending” issue without elaborating.

Texas Rangers general manager Jon Daniels said Sunday several players, including All-Star Joey Gallo, still needed to complete intake testing. He hopes it’s a startup issue that won’t persist.

“Once a player is tested and is through the intake process and is part of the team, on the follow-up tests, if things take longer at that time, the player continues and stays on the field with the team while these follow-ups are going through,” Daniels said. “It’s just, the front end is taking longer than I think it will throughout the year.”

Not every team is dissatisfied with the testing process. Milwaukee Brewers manager Craig Counsell said medical director Roger Caplinger is making things go smoothly.

“There’s a lot of hard work that goes into the logistics of setting this up,” Counsell said Monday. “There’s going to be snags in this. I think we all know that. But I’m pleased with how it’s gone so far.”