Manchester United defender Rio Ferdinand has hailed the impact of Robin van Persie this season.

The pair have become close as Ferdinand drove Van Persie to Carrington daily for training.

"Robin has been a big factor," said Ferdinand. "Last season, we lost on goal difference which tells you that we didn't score enough goals. We brought in a man who was top scorer last season and he looks like he is going to do that again this season. He has definitely added to what we had already."