The 33-year-old has not featured for the La Liga leaders since a 1-1 draw at Valencia on Feb. 3 and had to pull out of the Spain squad for this month's friendly against Uruguay.
"We hope that he'll make it but we'll see how things develop," Roura, who is standing in for Tito Vilanova while he recovers from throat surgery, told a news conference.
As well as Xavi, Barca will be without forward David Villa for Saturday's La Liga game at Granada, Roura said.
"It was a setback that disrupted his rhythm," Roura said.
Real, four points behind Atletico in third, host Rayo Vallecano in Sunday's late kick-off.
"We are focusing all our efforts on the Granada game because the league is key for us," Roura said, adding that he may rotate the squad to rest some players for the Milan clash.
"We are in a comfortable position but that should not be an excuse for any king of relaxation.
"The part of the season is coming when there is a lot at stake in only a few days.
"From a physical and psychological point of view we are in good shape."
