Liverpool star Steven Gerrard on Monday predicted a wide-open Premier League season with several teams challenging for the title.
Liverpool and Manchester United have both splashed out on summer signings while Chelsea and Arsenal remain dangerous, he said.
"You expect all the big clubs to make signings and there's also clubs that finished below us that are making big signings," said Gerrard, in Hong Kong for the Asia Trophy tournament.
"Chelsea are upset at losing out to Manchester United and Arsenal have young players who have more experience now. I think it will be a tough title race this year and I think more teams will get involved."
Portsmouth coach Harry Redknapp, whose team face Fulham in the opening match on Tuesday, said it could be the most hard-fought season yet.
"It's going to be a very tough Premier League -- the toughest in history," he said.
"Lots of teams have improved -- Fulham have brought in players and so have Sunderland, West Ham and Newcastle."
Liverpool have brought in Fernando Torres, Ryan Babel, Ukraine striker Andriy Voronin and Yossi Benayoun while Manchester United are hoping Carlos Tevez will join new signings Owen Hargreaves, Nani and Anderson.