The fullback is on-loan from Liverpool and been superb this season.
Charles believes Bradley has "all the tools to go on and have a very successful career".
"I've been winding him up the past few days," Charles joked about Bradley spurning a gilt-edged opportunity in Saturday's win over Peterborough after being played in by the striker.
"There was actually another one later on in the game where he has mis-hit it and said to me, 'I'll have to cut you a bit of slack, it's harder than it looks'.
"He has been great for us. He has been scoring goals and playing well.
"It's great to build relationships with players [at club level]. Things become second nature.
"You know the movements they make and where they want the ball, so me and Conor have quite a good relationship."