Manchester United boss Jose Mourinho says he has no idea why Chelsea allowed Nemanja Matic to join the Red Devils.
The Serbian was United's best player in their inaugural game of the English Premier League against West Ham United.
He moved to Old Trafford for £40million to become the Portuguese's third summer signing.
"I didn't disturb him, I didn't disturb Chelsea," Mourinho told reporters.
"It looked like something was happening because his agent told me we can have him, that we just had to pay.
"It depends on what is happening or what was happening behind doors and we don't know.
"The only thing I know is that I brought him to Stamford Bridge because I thought he was a player with special qualities and since I left I always thought he could be a perfect player for us.
"We have him and we are very happy because he is a player that our team needs."
