Manchester United's Phil Jones awaits news on the severity of an ankle injury which forced him off during the 2-1 FA Cup fifth round win over Reading at Old Trafford on Monday.
Jones was replaced by Nani after 42 minutes following a challenge with Royals captain Jobi McAnuff, with the 20-year-old later seen leaving on crutches.
Second half goals from Nani and Javier Hernandez sent United through to the quarter final, before McAnuff halved the deficit late on. However the result was marred by injury to Jones and manager Sir Alex Ferguson says the England international will miss the weekend trip to Queens Park Rangers.
"We'll have to assess it in the morning," he told BBC Sport. "It's an ankle injury obviously so I'd imagine he'll not be ready for Saturday anyway. But we'll see what he's like after that."
While Hernandez netted his 14th goal of the season from just his 15th start, it was Nani who stole the show, providing a timely reminder as to the quality he possesses amid a season disrupted by loss of form and injury.
And Ferguson was full of praise for the winger, who has of late been linked with a move away from the Premier League leaders.
"It was a really good cup tie, when they got the goal they went for it and piled men in the box," he said "We played some great football and could have scored a lot of goals tonight.
"I'm satisfied with the quality of our play. We should have punished them better though. At 2-0 you are never comfortable. Nani deserved to be man of the match, his contribution was terrific.
"I had a feeling he would win the match for us. We are at home in the next round and we would take that against anyone."