Wayne Rooney believes Manchester United team-mate Marouane Fellaini has gone from Old Trafford scapegoat to one of the most dangerous forwards in Europe.

Fellaini was one of the stars of United's Manchester derby demolition of neighbours City on Sunday and was recently described as almost undroppable by manager Louis van Gaal.

Now Rooney has revealed his admiration for the former Everton forward, saying: 'He is getting used in the right way. He is a handful for defenders to mark.

Marouane Fellaini has enjoyed an upturn in fortunes in recent week at Manchester United

'We like to play out from the back and if teams are pressing us then we have him as an option.

'He is probably the best in world football at bringing the ball down and getting us out of that pressure and further up the pitch. He is being used in the right way by the manager and he is repaying the manager with goals and good performances.'

Fellaini was signed from Everton by Van Gaal's predecessor David Moyes in the summer of 2013 but endured a terrible first season as he suffered with injuries and tried and failed to establish himself as a holding midfield player.

Wayne Rooney hailed his Belgian team-mate as one of the best in world football at the moment

Fellaini has proved a handful for defences and was instrumental in wins over Manchester City and Liverpool

Now the Belgian has emerged as a potent attacking weapon under Van Gaal, used as a second striker behind Rooney. On Sunday, City couldn't cope with him just as Liverpool had suffered at his hands at Anfield three weeks earlier.

'Last year was awful for him but in fairness he kept his head down worked hard and come through that tough period,' reflected Rooney.

'He is showing now what he did at Everton and why Manchester United bought him.

'He is a quality player. He is a different option for us. It is starting to show on the pitch.

'It was tough for him but he had the whole team's support. We knew he was working hard and it wasn't just him struggling last season a lot of us were.

'He was the one who took most of the blame for it. It was hard for him. Thankfully the manager has shown faith in him.

'He is big and he is strong and always a goal threat which he is showing now. He is awkward to mark. It is great for him and we hope it continues.'

Fellaini wheels away after heading in at the far post to beat Joe Hart and give United the lead in the derby

United are now in third place in the Barclays Premier League after six league wins in a row. This weekend they travel to Chelsea with renewed hope.

'We said earlier on in the season that we were working on things and it was going to take time,' added Rooney.

'It is starting to show now, the training we have been putting in.

'We have been working really hard.

'Each game is different and we have been training for each game in a different way depending on how the opposition plays. There is no detail left unturned. We have been prepared really well.'

'We are confident going to Chelsea.

'We are in a good run of form and have beaten some good teams. It is a big test for us at Chelsea.

Louis van Gaal suggested that Fellaini is almost undroppable at the moment and hailed his rebirth

'They are top of the league and it is always tough at Stamford Bridge. They are in a very commanding position. We just have to try and win our games and finish as high as we can.

'We are still a work in progress. We are still learning. It is great how things are going and the performances we are putting in but it is has to continue.