Juan Mata admits it will be "weird" facing Wayne Rooney when Manchester United welcome Everton to Old Trafford on Sunday, live on Sky Sports Premier League.
Rooney, United's all-time leading goalscorer, faces his former side for the first time since ending his 13-year tenure at Old Trafford to return to Everton.
The Toffees are without a league win since the opening day of the season and have suffered back-to-back losses to Chelsea and Tottenham in the Premier League, but Mata is wary of the threat they will pose.
"They've just suffered a tough defeat against Tottenham, but they have made very good signings and of course they have a player like Wayne Rooney," Mata wrote in his weekly blog, One Hour Behind.
"I hope Old Trafford will welcome him as he deserves.
"It will be weird to see Wayne playing with a different shirt, to be honest, but this is the decision he made last summer and we wish him the best of luck."
First, however, Champions League football returns to Old Trafford after a one-year absence as Manchester United take on Basel and Mata is excited to once again be competing against Europe's elite.
"The group stage of the Champions League kicks off and we are back there, with the best teams in Europe, the place where Manchester United should always be," Mata said.
"We missed it a little bit last season - although we made the most of our year in the Europa League with that night in Stockholm - and now it's time to compete at the highest level."