Phil Jagielka knows Everton team-mate Marouane Fellaini makes life 'frustrating as hell' for defenders after struggling to contain him in training.
The Belgium midfielder proved to be a constant thorn in Manchester United's side on Monday as he put in a dominant display, which included the match-winning goal, in a 1-0 victory for the Toffees.
Jagielka was not surprised to see the powerful Belgian troubling a Premier League heavyweight, with the talented 24-year-old capable of causing problems to the best in the business.
The England international admits it is difficult enough keeping Fellaini quiet on the training ground, never mind in a competitive fixture.
"It's a little bit different in training as you can kick him, pinch him and pull his hair and get away with it but when he is switched on like he was it is nearly impossible to mark him," said Jagielka.
"He's about a foot taller than me so there's pretty much nothing you can do other than stay behind him and give him a little bit of a nudge and hope he has an off day with his touch and his passing.
"As a centre-half you can try to nick on front of him but he is strong enough to hold you off so you have to stay behind him and hope he's not having a good day.
"I know what it is like and it is frustrating as hell and when he is clever enough to bring it down and pop it off to players who play a deadly ball it makes us hard to play against."
Fellaini has been granted greater freedom to express himself in the wake of Tim Cahill's departure, and Jagielka believes an attacking unit which also includes Nikica Jelavic and Steven Pienaar will cause its fair share of problems this season.
"We do look dangerous when he is in that form and when players around him - Steven Pienaar and Leon Osman - are playing well it takes some pressure off Jelavic as a target man," he added.
"I am sure teams will try to find ways to stop us but Felli is a good player and he will find other ways to get on the ball and be dangerous for us."