(AP) — COVID-19 didn’t keep Miami center Bam Adebayo out of any games last season, even though he tested positive for the virus not long before the NBA’s restart bubble opened.

He missed two games last week because of the virus — without having the virus.

Adebayo is one of many players sidelined at some point in recent weeks by contact tracing, the method of figuring out who may have possibly been exposed to a person who has tested positive for COVID-19. It has been a major factor in the decisions to postpone 20 games so far this season, including the latest three Memphis Grizzlies’ games that the league decided Thursday to push back.

“As much as we may complain about it, it’s only for our own benefit,” Washington’s Bradley Beal said.

Beal missed a Jan. 9 game while going through contact tracing, a process in which the NBA and its teams take a deep dive into who people have been around over a two-day period once someone tests positive.

Everything is examined — who might have shared a car ride with whom, who sat where on the team plane, who had dinner with others and what their whereabouts have been. Even the cameras that have been used for advanced stat tracking during games are utilized, just to see how long one player may have been in close proximity of someone else during a game.

“I think we’re doing as well as we can be, during what’s a very difficult time, not just for the NBA but for a lot of people in the country,” said NBA senior vice president David Weiss, who helps oversee all the health and safety efforts for the league. “And I think we’re doing that well because everybody — from players, staff, families — is making some shared sacrifices to try to do as well as we can.”

The NBA has some staff with public health backgrounds, who knew what contact tracing was before it became a buzz term in the sports world a few months ago, to assist in the process. Players get asked a series of questions; examples include if they played 1-on-1 against anyone in practice, if they’ve recently gotten a massage or therapy, was the person administering that treatment wearing a mask, or if they’ve recently socialized with others for more than a few moments.

The answers help create the path for investigators to follow.

The biggest culprits that have led to players being flagged and ruled out during the contact tracing process: meals and shared rides, improper mask usage. The smaller the area where people are congregating, the smaller the air volume, the higher the risk — and the NBA has been telling teams that since the protocols for the bubble were established back in June.

“Contact tracing involves a lot of different sources and information,” Weiss said. “The core of it is interviews, to the stats that we collect digitally, to pictures of spaces, to all to all kinds of different things. And the information technology is helpful.”