The former Manchester United youngster got his career back on track under the guidance of Blues manager Lee Clark and the Hammers assistant is now hoping he will continue to make progress in a West Ham shirt.
McDonald told whufc.com: "He has certainly grown up a touch. With all due respect, when he first came from Manchester United he thought he was the top kid and he was going to walk straight into our team and it certainly doesn't work like that.
"We sent him away to get the experience at Birmingham and he's certainly come back and he's used that experience.
"He had some experience around him as well [in midfield] with Kevin Nolan and Mark Noble pulling and pushing him, as you'd expect. If we can get him on the ball in the final third then he can produce and he's produced two goals on Monday.
"He missed his penalty at the end but that's good experience for him. He's come back in good shape, just like the rest of them."
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