The 22-year-old missed Sunday's Dundee derby and tweeted on Monday: "Absolutely gutted. Got an X-ray this morning on my injury and I have fractured my fibula."
United, who were paired with Celtic in Monday's Scottish Cup semi-final draw, are currently in eighth place in the SPL standings under new boss Jackie McNamara.
Russell sustained the injury in the 0-0 draw with Inverness last week.
 
Scottish Premier League Without Celtic 12/13. Click here to bet.







