The Philadelphia 76ers are starting to get fully healthy once again. Before this past weekend, the team missed its star center Joel Embiid for a little over three weeks due to a knee injury. On Saturday night, the big man returned.

When Sunday's game against the Memphis Grizzlies rolled around, the Sixers ruled Embiid out since it was the second night of a back-to-back. In addition to Embiid, the Sixers were also forced to suddenly play without the rookie guard, Tyrese Maxey too.

Despite going through pregame warmups on Sunday evening, Maxey was told he would have to go home early. According to the Sixers, the rookie guard was entered into the NBA's health and safety protocol. 

Following the blowout loss to the Grizzlies, Sixers head coach Doc Rivers revealed that Maxey had returned an inconclusive COVID-19 test half an hour before the game. Therefore, he didn't have enough time to get tested again before tip-off.

"Just the protocol," Rivers said in regards to Maxey's absence on Sunday. "[He had an] inconclusive test. You know, it's a shame too because this was a night where whenever Joel (Embiid) is out, we slide (Maxey) into the rotation. He can't catch a break right now. So, it is what it is."

On Monday, before the Sixers traveled to Boston, Maxey returned two negative COVID-19 tests, according to a team official. Therefore, he was cleared to travel as the team placed him on the injury report as probable.

Now that the Sixers are settled in Boston, the team has officially upgraded Maxey's status on the injury report to available. Along with Maxey, the Sixers also anticipate having Embiid back, leaving George Hill as the only member of the team who won't be available for them against the Celtics. 

Justin Grasso covers the Philadelphia 76ers for Sports Illustrated. You can follow him for live updates on Twitter: @JGrasso_ & Instagram: @JGrassoNBA.