Manchester United manager Sir Alex Ferguson has hailed the impact of substitutes Robin van Persie and Paul Scholes in this afternoon's 2-0 win over West Bromwich Albion.
The league leaders were ahead early against the Baggies but were made to defend for long spells by Steve Clarke's side.
Van Persie and Scholes came on after the break to deadly effect, with the Dutchman making the game safe with a curling strike in stoppage time.
Ferguson admitted that rotation will be key in the second half of the season and was delighted with the pair's impact from the bench.
He told BBC Sport: "Van Persie changed the game for us. When I brought him and Scholes on they settled the game down.
"West Brom dominated in the second half and kept pumping the ball into our box. They did very well. The ball came in and we had to head it out, and we did that better than we have done all season.
"We're in a good position. We're halfway there. We've a game on Tuesday away from home at Wigan and we've got a few players to freshen it up. We'll look forward to the next game and try and win it."
The Red Devils head into the new year with a seven-point advantage at the Premier League summit.
