The 23-year-old had been hoping to stake a claim to a first team place at Manchester United this season, but he looks set to miss the rest of the campaign through injury
The 23-year-old picked up the injury moments after coming on as a 71st-minute substitute in United’s 3-0 FA Cup win at Shrewsbury in February, but initially attempted to continue in his desperation to make an impression on the Red Devils’ first team.
And after his groin failed to show significant signs of recovery in the week following the Shrewsbury fixture, Keane was sent by the club to the United States in a bid to clear up the problem once and for all.
Keane, who was recalled from a season-long loan at Preston North End in January, posted a photograph on his Instagram account on Wednesday proclaiming a positive first day of rehabilitation.
Louis van Gaal has seen a number of first team players suffer long term injuries this season and is still waiting for Wayne Rooney to return to action.