Gregory applied for reinstatement in early July, and although he says he's ready to play, he's still waiting.
One of the issues Gregory raised is related to COVID-19 testing. The league wants a testing record from the player, but it hasn't tested him for six months because of the pandemic, a source told Charean Williams of Pro Football Talk.
"I really miss playing football and being a player in the NFL," Gregory wrote on Twitter. "I'm doing everything that is asked of me and I'm in great shape physically, mentally, and emotionally, but I'm being held back from furthering my career because of COVID and testing.
"I've been ready to play and test for months but still have gotten little to no help to resolve my reinstatement," he continued. "I'm asking more questions than I'm getting answered. It's amazing that the powers that be can keep passing the buck and also use this pandemic as a way to prevent me from joining my team. Telling me to just sit and wait in limbo over things I can't control, all the while doing everything right off the field, is unfair and flat-out wrong!"
The NFL suspended Gregory indefinitely in February 2019 for violating its substance abuse policy and the terms of a previous conditional reinstatement. That was the fourth suspension the 27-year-old had received since entering the league in 2015.
Gregory was suspended twice in 2016 and drew a year-long ban the following season. He was reinstated in 2018 and played in 14 games, recording career highs with six sacks and two forced fumbles.
A former second-round pick, Gregory has played in just 28 regular-season games throughout his career while missing 52 contests - 46 due to suspensions.