Soccer-Injured Bailly may need surgery, says Mourinho

* Managaer says Bailly picked up ankle injury with Ivory Coast

* Mourinho hoping conservative treatment works before surgery (Updates with detail on injury)

MANCHESTER, England, Dec 13 (Reuters) - Manchester United defender Eric Bailly may need surgery on the injury that has kept him out of action since early November, manager Jose Mourinho said on Wednesday.

Bailly had trouble with his groin after returning from international duty with the Ivory Coast in October but has been sidelined with an ankle injury.

"I think it is serious. I don't know (how long he will be out). It is an injury that came from the last time he was with the national team," Mourinho said.

"We are trying a conservative treatment but if the treatment is not resulting then probably it will end in a surgery procedure but let's wait a little bit more," he added.

United, with Chris Smalling and Phil Jones in the centre of defence, beat Bournemouth 1-0 on Wednesday. Mourinho also has Marcos Rojo and Victor Lindelof as options in the back line. (Reporting by Simon Evans, editing by Ed Osmond/Greg Stutchbury)