Boro's Bates has been plagued by injury problems

Bates, 21, sustained the injury in Norwich's draw against Hull City and will now require surgery on the knee for the third time in 18 months.

"We were hoping it was only minor damage," Norwich manager Glenn Roeder told his club's website.

"Unfortunately, our worst fears were confirmed. He sustained more than minor damage and needs an operation."

Bates impressed during his three appearances for the Canaries and looked like making a big impact at Carrow Road.

Roeder added: "He was really enjoying his time here and was showing what a good signing he was."