While his own career is definitely taking off again since the band's collapse, the lovely lad is concerned about pal Matt, who is in rehab.
Chatting exclusively to 3am at the launch of the MAC Viva Glam lipstick at London's swish Home House, he revealed: "I've been really worried about him, but haven't been able to speak to him since he's been in the Priory.
"I've left messages but I guess his therapists think it's best he has time on his own".
James, 21, added: "I think he was really sensible in deciding to check himself in.
"He's been in the studio and he's got some great stuff coming out, so I think he just wanted to get in control of his life before it got too serious.
"I know he'll be absolutely fine and raring to start performing again."
James also revealed that he's set to release an album with his new band in the summer.
"I've got loads of new tracks laid down and I'm really happy with them. The new stuff's got a Busted vibe, but with a slightly harder edge." Looking back at Busted's surprise split in January, when Charlie Simpson quit to concentrate on his band Fightstar, James said: "It was the strangest thing. One minute we've got these manic schedules and the next we've got nothing to do.
"After four days I felt like I was going mad so I just went back in the studio to get a sense of normality.
"I wrote some of the tracks for McFly's next album in that time, so it was productive".
But despite admitting that he "hardly ever" hears from 19-year-old Charlie, James longs to give Busted a proper send-off.
"If Charlie agreed to it, Matt and I would do a reunion tomorrow. "We never realised that last date in Wembley would be our final show - if we did I'd have done something mad on stage. I think we owe the fans a proper farewell tour. But I'm just glad to get another crack at doing what I love best."