Jose Mourinho
Mourinho worked as van Gaal's assistant at Barcelona for three yearsReuters

Chelsea boss Jose Mourinho is certain that new Manchester United manager Louis van Gaal will be able to turns things around at Old Trafford despite the Dutchman getting off to a very poor start.

Van Gaal, who led Netherlands to a third-place finish in the 2014 World Cup, was brought in to replace David Moyes, who was sacked following Manchester United's disappointing performances in the Premier League and other competitions last season.

Despite doing very well in preseason, winning all their fixtures against some tough sides including Real Madrid, Roma, Inter Milan, Liverpool and Valencia, the Red Devils kicked off the 2014/15 season with a home defeat to Swansea City.

After that United were only able to draw against Sunderland in the Premier League, before suffering a humiliating 4-0 defeat the hands of League One side MK Dons.

They were also unable to beat newly-promoted side Burnley in the next Premier League fixture as the match ended in a goalless draw.

However, now that United have spent in excess of £150 million in the summer transfer window, bringing in some talented players including Angel Di Maria and Radamel Falcao, Mourinho says that he is confident that van Gaal will do well at Old Trafford this season.

"He is one of the best managers in the world so I think he is a man with great experience for the job," Mourinho, who worked as van Gaal's assistant at Barcelona for three years, told Eurosport-Yahoo. "Manchester United is a big team [and] he is a big manager so I think they will do well together."

Meanwhile, Chelsea's start to the 2014/15 season has been quite the opposite in comparison to United. The Blues are currently sitting at the top of the Premier League, with three wins in three fixtures.

And Mourinho feels that Chelsea's strong start to the season is due to the addition of new players including Diego Costa and Cesc Fabregas, who have both been impressive.

"It's a direction we tried to establish since the beginning of last season, but our squad now is different. We have different qualities now in our players," Mourinho said.

After failing to win a single piece of silverware at Stamford Bridge last season, Mourinho is confident that the Blues are heading in the right direction.

"The second season normally is a good season for a manager because you come from one season of work and you can choose a better direction you want to go and we feel comfortable and we feel happy the way we are doing things."