The North-West outfit have a chance of qualifying for the semi-finals of the elite European competition having secured a 1-1 draw with Bayern Munich at Old Trafford on Tuesday.
Before that, the Red Devils will have to go head to head with the Magpies at St James' Park on Saturday.
"The only thing we are thinking about is the Newcastle game," Moyes said in Friday's press conference. "The focus is all on Newcastle. We have to go up there and put on a good performance and get three points, trying to build a little bit of momentum towards the end of the season. We will go there and try to do that.
"Obviously I have got other things on the mind, but the focus is Newcastle and we will try to balance things out correctly. We have got an extra day's recovery.
"Saturday to Wednesday is better than last week when it was Saturday to Tuesday, but the message to the players is that it is Newcastle United, this is the next game and it is the most important one."
United are currently seventh in the Premier League table, 10 points adrift of fourth-placed Arsenal.