Ramos was replaced in the 71st minute of the European contest, although it was first thought that the centre-back's withdrawal was due to the fact that he had picked up an early yellow card in his team's 3-1 win.
The 30-year-old, however, has confirmed that he "suffered a blow" which damaged his hip and adductor, although the defender is hopeful that the injury is not a muscular problem.
"I suffered a blow and I hurt my hip and adductor. I held on as I could until I thought the result was good, to wait for the tests. Hopefully it's not anything muscular," Ramos told reporters.
Real Madrid return to La Liga action with a home game against Espanyol on Saturday afternoon.