He told BBC Radio Kent: "I've had so many lovely messages from people who are just as frustrated as myself.
"The next day on my phone I had a lot of text messages and calls from the boys. We're a real squad."
Birchall has only just joined the Gills from Dover Athletic, following manager Andy Hessenthaler to the Medway club.
The Gillingham boss said he was sickened by posts on internet message boards gloating over the striker's injury.
Birchall said he was only paying attention to the kind words.
"It's part of football. People probably don't mean what they say. Sometimes people say it because they think other people want to hear it.
"I've only seen positive stuff and I'm grateful to all the people that have sent me messages," he said.
Birchall is likely to be on crutches for a further two months before stepping up his rehabilitation but the former Arsenal frontman said he might get agitated as an onlooker.
"I need a lot of patience which I'm not very good at."
He added: "It's going to be a lot of waiting around and just making sure that it's all bonding right and then I can start strengthening after that. I think in the next couple of months I'll be able to start weight bearing."
In his absence, Gillingham are likely to employ fellow new boy Danny Kedwell as a lone striker, though Hessenthaler is aiming to bring another forward to Priestfield for the start of the season.
Source: BBC Sport
Source: BBC Sport