Ollie wrote in the Sunday Mirror: "The last time I saw Charlie was when he came to see last season's play-off final.
"We were with Paul Ince, who told him he should have gone to Liverpool and walked in the door like he owned the place.
"If you don't have that massive confidence at a big club, it can be really hard to flourish.
"I hope that Tony Pulis gets into his head and makes him believe in himself again, like I was able to.
"If so, we'll see him hitting the top of his game again."