Aberdeen's Ryan Jack out for three months

Aberdeen defender Ryan Jack

Aberdeen defender Ryan Jack will be out of action for up to three months with a broken foot picked up while captaining Scotland Under-21s for the first time.

The 20-year-old was injured in Friday's 2-0 defeat by the United States in the Marbella Cup in Spain.

Jack said on Twitter: "Been to get my foot x-ray. Bone is fractured need a operation.

"Looking at 10-12 weeks. Gutted but will come back fitter and stronger. Op end of this week or start of next."

Jack lies injured while on Scotland Under-21 duty

Jack has been a regular in the Aberdeen side since breaking into the squad in 2010.

He has also played in midfield but has mainly slotted in at right-back for manager Craig Brown.

Aberdeen confirmed on their website: "Following consultation, it was confirmed the fracture will require surgical repair.

"Ryan is expected to be out until the end of January."

Meanwhile, Dons boss Brown is hopeful that winger Ryan Fraser will be fit for the trip to Dundee United this weekend despite picking up a knock while playing for Scotland Under-19s.

Fraser came off after 52 minutes of Thursday's 1-0 win over Romania as Scotland topped their group to reach the elite round of qualifying for the European Championship finals.

It was feared the player would be out for a lengthy spell, but Brown has allayed those fears.

''It's just a slight strain - I'm hoping he'll be back for game at Tannaice,'' Brown said.