The 22-year-old has been out of action since April and is yet to kick a ball in anger this season. The defender has been plagued by a troublesome groin injury and is only just starting on the road back to recovery.
But while his own injury has been frustrating enough, Alton has also had to endure the annoyance of sitting and watching our defenders picking up knocks of their own, only to miss out on any call-up to replace them.
Now though, there does seem to be some light at the end of the tunnel for the Holloway-born versatile player and obviously he can't wait to get back.
"It's been five months now, so I'm hoping I'm coming to the end of it soon," says Alton. "It was back in April that I felt my groin area getting sore after games and in the end it got to the point where I couldn't play anymore.
"It was diagnosed as inflammation of the pubic bone and I was told I had to rest."
Although only featuring for the first team on three occasions last season, all as substitute, Alton was a regular for the Reserves and made 18 starts for Colin Calderwood's side, more than any other player.
But his last competitive action was in the Reserves' 1-0 win at Watford in March and five months of rest appear to have done the trick.
"I've been doing strengthening work on the affected area for a while now and it's not too bad at the moment," Alton reveals. "I'm feeling good now and want to push on and get back into training.
"It certainly has been frustrating though, especially when you look at the defensive crisis we've got at the moment. You can't help but think you might have got a chance, but that's life.
"I just need to concentrate on getting fit now. There's no real time scale for a return, it's one of those injuries where only I can say when there's no pain. As I said, I feel good at the moment, but until I go out and play some football, I won't really know when I'll be back."
Watching from the sidelines this season however, Alton is delighted with the way the campaign has begun.
"We've made a great start, we're looking good," he says. "Attacking wise, with Matty and Simon down the wings, we look frightening at times and with Robbie now here, we will only get better. We know what a great player he is and he's already showed us some glimpses of what he's about.
"I reckon we're good enough to stick around near the top of the table this season."
By Jon Rayner
Alton Thelwell could be forgiven for thinking he is something of a forgotten man at the Lane.