St. Louis Cardinals assistant general manager Moisés Rodríguez has been expecting the news that came down Friday.

“At seven in the morning when my phone rings, I sort of panic because it might be that phone call,” he said.

After 20 years in baseball ranging from media relations to international scouting, Rodríguez is in a role he never imagined — contact tracer during a coronavirus pandemic.

Dozens of team employees across Major League Baseball have been entrusted to carry out the critical task, a pillar of the league’s plan to operate a 60-game season while COVID-19 continues to assail much of the United States — and has caused the postponement of 16 games in the first week of the season. The job requires sensitivity and diligence, and it relies on trust between players and their employers to keep personnel safe and the season alive.

Rodríguez spoke to The Associated Press on Tuesday, three days before it was revealed that two Cardinals players tested positive for the coronavirus, leading to the postponement of Friday’s scheduled game in Milwaukee.

Prior to Friday, Rodríguez had completed one other contact tracing investigation, at the onset of preseason camp when at least two players were flagged during intake testing. He spoke to the AP about his experience.

“It is new, I’m sure, for a lot of people,” Rodríguez said.

When a positive test is returned — whether it’s an isolated individual like Washington Nationals star Juan Soto, or a team-wide outbreak like the Marlins — contact tracers are immediately tasked with investigating carriers’ interactions. Infected persons are asked to thoroughly recount the 48 hours before they tested positive or first showed symptoms, so any team or league personnel found to have had close contact can be tested and quarantined to help stem the spread.

The league’s tracing does not extend to non-team personnel, such as employees at hotels, but efforts are made to alert public health entities as well as enmeshed companies.

At least two employees for each club were appointed in June for tracer training. The league suggested that medical staff and bilingual employees were ideal fits, but the decision was left to teams.

“The main requirement is attention to detail,” said Bryan Seeley, senior vice president and deputy general counsel for investigations, compliance and security at MLB, whose department oversees the program.