Cape Town - Chelsea forward Radamel Falcao acknowledges that it isn't easy to adapt to the unique challenges of the Premier League.
The Colombian netted only four goals in 29 appearances for Manchester United and is aware of the demands of EPL.
"It's a lot more physical here than anywhere else in Europe," Falcao told Chelsea's website.
"It's a very, very competitive league where each team gives absolutely everything they've got in every game they play.
"It demands 100% of your ability and focus because it is very competitive, very physical and tactical too.
"Maybe the football philosophy is a little different here in that it is always about getting the ball forward and there is less time when teams are just trying to control the ball and take the heat out of the game."
Other than Falcao, Asmir Begovic is the only other new arrival, brought in from Stoke to replace departed goalkeeper Petr Cech, although Mourinho is keen to bring in a left-back as back-up for Cesar Azpilicueta.
The Blues boss [Jose Mourinho] doesn't get many things wrong, but if Chelsea's title defence falters, he will find himself accused of failing to build on a side that won the title at a canter.
The likely absence of Diego Costa would provide Garry Monk's Swansea with a welcome boost ahead of one of their most testing fixtures of the season.
And Swansea captain Ashley Williams said: "At the moment I think the most difficult Premier League striker to play against is Diego Costa, he scored a few goals against us last season.
"He's one you don't look forward to playing against to be honest.
"It seems he might miss Saturday's game, but you never really know until you get to the ground and look at the team-sheet.
"Whatever eleven they field is world class so it doesn't matter too much, but obviously if he didn't play it would be a bonus for us."
Swansea are hoping to build on last season's success of finishing eighth in Monk's first full year in charge and the arrival of Andre Ayew from Marseille should provide an additional attacking threat this year.