He told reporters: "If you look at the league table, it is [the biggest challenge of the season]. I think Manchester United is a very good team, a top club in England that has spent a lot of money to even make the team better again. Same for Chelsea in this season. Chelsea does really well. If you look at the league table then they are the ones that might be our toughest opponent. But it's not always about the league table. Sometimes it's about the form of the day, it's about their game plan. We had some difficulty with Wolves as well, who are bottom of the league, I think. But it is a challenge, that's for sure."