Chelsea captain John Terry admits he is concerned by rival clubs' transfer activity this summer and believes six or seven teams will be challenging for the Premier League this season.
Chelsea looked to have the league title firmly in their sights last term but suffered a mid-season collapse before rallying to claim second place, nine points adrift of Manchester United. Terry believes Chelsea are strong enough to win their fourth Premier League title, but he believes the challenge will come from all sides.
United remain the team to beat, with manager Sir Alex Ferguson bolstering his title-winning squad with the likes of Ashley Young, Phil Jones and 'keeper David de Gea, while Wesley Sneijder has been frequently linked with a move to Old Trafford.
Chelsea have also spent money, but predominantly on their manager, with the Blues spending €15 million to buy Andre Villas-Boas out of his contract at Porto. Romelu Lukaku looks set to become Chelsea's biggest purchase of the summer, having had two bids rejected for Tottenham playmaker Luka Modric.
"I'm worried about a lot of teams this season," Terry said at the official launch of the Premier League season. "Everyone has strengthened. Manchester City and Manchester United have bought in some good players, Liverpool too. There are six or seven teams who can really push and have a chance of winning the trophy.
"We can catch Manchester United. They have been the benchmark for 20 years. We pushed them to the end last season but missed out. We all see their quality and hunger they and their manager have. It drives me on and seeing them lift the trophy still hurts to this day. I want to get my hands back on it."