The Eagles are preparing for the FA Cup semi-final against Watford on Sunday but experienced a little setback in the form of a disappointing 2-0 defeat to United at Old Trafford.
Damien Delaney's early own-goal and Matteo Darmian's superb strike 10 minutes into the second half downed a lacklustre Palace outfit who were perhaps keeping one eye on their trip to headquarters for the cup competition's final four in a few days' time.
"It's not the start anyone wants at Old Trafford - to concede after four minutes knocked us a little bit but our focus is slightly blurred as we have the semi-final on Sunday," he said.
"It's a big game for Manchester United (on Saturday) but it's much bigger for us as we could win a trophy. My players worked hard and some players got some game-time. The one bit of key news to come out of tonight is that we're fit and well for Sunday.
"I've been a player and you're kind of protecting yourself a little bit because you know it's a huge game for you personally.
"I couldn't fault my players effort - tackles were flying in and our commitment to the game. But it was just that little bit of focus, where you hurt teams, wasn't quite there tonight. That was probably due to Sunday."