Marvin goes under the knife.
The former Watford trainee hasn't appeared for the U's since the FA Cup tie against Tottenham and it looks like it will be a race against time for him to play again this season.
He went under the knife on Monday and U's physio Tony Flynn said he would be getting through the first stage of his recovery at home.
"Marvin has had a small spur of bone removed from the outside of his ankle, something that initially wasn't troubling him enough to miss games and training.
"It got steadily worse and unfortunately, we got to the stage where going in for surgery was required.
"He will spend the first couple of weeks at home recovering from the operation and then we'll have him back at the training ground with us."