Tracy Morgan is "still struggling with rehab."
The 46-year-old actor, who sustained a traumatic brain injury, broken femur, broken nose and broken ribs when a Walmart truck crashed into the vehicle he was travelling in last summer in New Jersey, has been making "slow progress" with his recovery, but isn't ready to return to work.
The former '30 Rock' star's lawyer Benedict Morelli said: "He's still struggling with rehab to get better. He's working hard to get well."
Tracy, who is getting regular physical, speech and cognitive therapy, was forced to miss the 40th anniversary special of 'Saturday Night Live' - on which he was a regular cast member from 1996 until 2003 - last weekend due to his injuries.
An insider told PEOPLE.com: "Tracy would have loved to have been there, but he just isn't up for it at this point."
His former co-stars Tina Fey and Alec Baldwin both honoured him during the show.
Tina said: "I wish my friend Tracy Morgan was here tonight, and I know that he was hoping that he was well enough to be here too."
While Alec added: "See you at the 41st, Tracy!"
Walmart recently reached a confidential financial settlement with the family of Tracy's close friend James McNair, who was killed in the car accident, and insisted it is "committed to doing what is right" for everyone else involved.