The Chelsea midfielder has joined Leeds on a season-long loan.
After completing his move, Luton-born Baker said: "I had a nice holiday and now I'm really excited for the season ahead.
"It's a massive club with amazing history so it's an great opportunity for me.
"A couple of weeks ago Leeds showed me what they want to do.
"The plan they have for this season, bringing in a new manager, how they want to play.
"If you know your football, you know he's a massive manager, he's managed some of the best in the world and he's got good aspirations for this season. We want to challenge and get promotion."