The NBA's postponement of three consecutive Memphis Grizzlies games mark an evolution in how the league's handling of COVID-19 scenarios within teams, essentially parking a team and taking them out of circulation once a roster has been exposed to the virus, sources told ESPN on Thursday.

In previous instances, the league has allowed teams to isolate positive players and sideline others in contact tracing believed to have been in close proximity to infected individuals -- yet still allowed teams to proceed with games if they had eight eligible players.

While the Grizzlies don't have several individuals placed into the league's Health and Safety Protocols, the NBA's temporarily shut them down in a way to similar to how the NFL closed team practice facilities during game weeks to keep players and staff away and limited exposure to spread.

The NBA postponed four consecutive games for Memphis -- including games Wednesday and Friday in Portland, and games Sunday and Monday in Sacramento. So far, the league has postponed 20 games this season.

The NBA hasn't released the second half of the league's schedule beginning in mid-March yet, waiting to account for what they expected to be a significant number of make-up games.

The Grizzlies have one known player -- center Jonas Valanciunas -- in the league's Health and Safety Protocols, and no others that they've yet to publicly announce. The Grizzlies are soon expected to travel back to Memphis.

The NBA had 11 positive tests among 502 players for the week ending Wednesday, and recently tightened restrictions on players in both home and away marketplaces. Players are no longer allowed to leave hotels on the road for almost anywhere but games and practices -- and outside guests are no longer allowed in players' rooms. The NBA and National Basketball Players Association agreed on a temporary adjustment of these protocols that they would re-evaluate again next week.