The 24-year-old was the dominant force throughout Monday night's match and capped an impressive performance with the only goal early in the second half. Jagielka is well aware of the 6ft 3in Belgium midfielder's talents having faced him in training every week but accepts it is a different prospect handling him in a competitive match.
"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 the centre-back.
"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."
With the departure of Tim Cahill over the summer manager David Moyes has more freedom to deploy Fellaini further up the pitch in an advanced role behind a lone striker, most likely to be Nikica Jelavic this season.
It is an option the Scot has employed before but Jagielka believes with the players he now has around him - Steven Pienaar re-joined in the summer and Jelavic is starting his first full season - Fellaini can be much more of a threat.
"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," added the England international.
"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."
Source: PA
Source: PA