Robin van Persie's partnership with Wayne Rooney is only beginning to blossom, according to Sir Alex Ferguson.
The top two goalscorers in last season's Premier League are now in tandem at Old Trafford, and Van Persie's strike against old club Arsenal on Saturday was the 12th registered by the pair this term.
Rooney has been used in a deeper position than normal in some games, and Ferguson reckons the flexibility of both players is the key to their promising relationship.
He said: "There's flexibility there and the right type of movement. They also both have the courage to play in these positions. Robin's not far away in that respect.
"They're both mobile players and good footballers with a great desire to play and win. I don't think you saw the best of them as a partnership against Arsenal."
Van Persie said: "You have two positions, the nine and the 10, and we are both nine and a half.
"We are just helping each other out. We both play behind and a bit higher up. It seems to be working well and I am very happy with Wayne - hopefully we can keep it going."