Aston Villa midfielder Jack Grealish could be out until next year following a freak injury that has left him hospitalised with kidney problems.

The 21-year-old was kneed in the ribs during a pre-season friendly with Watford on Saturday - a tribute game for the late manager Graham Taylor - and was subsequently taken to hospital.

Villa manager Steve Bruce said that he expects Grealish to be out for at least two to three months but admitted that it 'could be even longer'.

"He's poorly at the minute," Bruce told reporters today. "I went to see him in hospital yesterday. [It will be three months] at least.

"It's very painful and he's still in hospital, which tells you something about the extent of the injury.

"We wish him a speedy recovery because the kid's still in a lot of pain."

Grealish made 31 Championship appearances for Villa last term, scoring five goals and registering two assists.