Maxwell was expected to miss six to eight weeks after scans revealed the fracture following Collingwood's round two win over Carlton, but the Pies captain will line up against the Dockers in Perth on Saturday night.
"I wasn't actually expecting to get to this point and be here today, but early on in the week we had our scans to check how everything was and everything was healed, and we didn’t see any damage there," Maxwell explained.
"That's when I knew if I could get through training and function, and do what I need to do then I'd be right."
The 29-year-old said there was no risk involved in him returning after only four weeks out.
"No, not at all. We wouldn't take the risk,” he said.
"After missing four weeks you'd wait another week, or two weeks, if there was a risk involved.
"Obviously I saw the specialist and he was very happy with how it had all healed, and here I am."
Both Collingwood and Fremantle enter Saturday night’s match with 4-2 records, both dropping matches to Hawthorn and Essendon.
Maxwell said it was a credit to the depth of both sides given the injuries that both squads are carrying.
"Both teams have got probably three or four of their best 10 guys not playing,” he said.
"I think both teams have showed that they've got a lot of depth and they can cover those guys.
"That's what the 4-2 start for both teams shows."
The Magpies have dominated recent encounters with Fremantle, winning their last four, including two at Patersons Stadium, and six of the last seven clashes.
But Maxwell said his side was very wary of the challenge the Dockers posed.
"It's going to be a tough game. All Ross Lyon coached teams are,” he said.
"They're very defensive. They've got that flash of brilliance with guys like (Michael) Walters and Hayden (Ballantyne) up forward, so it's going to be a big challenge for us. But we love travelling, we love getting away as a team and we've got a good record going interstate."
Collingwood has a remarkable recent record outside of Victoria, winning 14 of the last 17 matches played away from Melbourne.
Maxwell said his team was united despite Collingwood players making public comments about their current and former teammates on various media platforms in the last few weeks.
"I think a lot of it, particularly with current players, we don't really mind if we're talking publicly about our other current players because we really need to make sure that everyone is on that knife-edge and playing that way.
"We expect a lot of each other. I think it's something you'll see a lot more of from other clubs as well."
