Bristol City boss Gary Johnson will not waste any time feeling sorry for under-fire Portsmouth supremo Tony Adams when their clubs collide in the FA Cup on Saturday.

The pair forged a firm friendship when studying together for their UEFA Pro-Licence badge last year and Johnson has since followed the former England and Arsenal skipper's career with interest.

But that won't stop him trying to heap the pressure on Adams by knocking the holders out in this weekend's Premier League versus Championship third round encounter at Fratton Park.

Eager to enhance his own reputation as a manager, Johnson nevertheless feels a degree of sympathy for his opposite number, who has come in for criticism from irate Pompey fans since succeeding Harry Redknapp in the Fratton hot-seat in October.

He said: "They can teach you how to be a good coach, but they haven't yet invented a man-management course to teach you how to handle Premiership superstars. How do you begin to try and motivate young millionaires? Some managers are natural motivators, but others don't know if they're cut out for it until they try it for themselves.

"Tony has been given an opportunity and he's doing his best to take it.

"He's travelled all around the world studying different coaching methods and served his apprenticeship in the lower leagues with Wycombe and as Harry's number two.

"But none of that can possibly prepare you for having to deal with Premier League internationals and only time will tell if Tony will make a go of it or end up going the same way as Paul Ince (sacked as Blackburn manager last month)."

While Johnson will be doing his best to undermine Adams on Saturday, he believes the rookie Premiership boss should be given more time to prove himself.

Adams is coming under mounting pressure in the wake of a worrying downturn in results which has seen Pompey slip to below halfway in the Barclays Premier League.

And sources on the south coast suggest the former England and Arsenal captain could be on his way out of Portsmouth if the FA Cup holders suffer defeat at the hands of underdogs City.

But Johnson reckons talk of Adams' imminent demise is premature and is backing one of England's brightest young managers to come good in the end.

He said: "People talk about Tony Adams being under pressure and it seems crazy to me.

"He's only been in the job a few months and needs time to stamp his authority and make his mark in the Premiership.

"I know Tony quite well and I have a lot of time for him," claimed Johnson. "He's a young up and coming English manager and he deserves support rather than criticism.

"I'm sure he'll get it right at Portsmouth and be a success – but he needs to be given time. It's a reflection on football and society that, these days, as soon as things start to go wrong, people call for the manager to be sacked."

Since taking over from Tottenham-bound Redknapp, Adams has presided over seven defeats, five draws and just three victories. An early FA Cup exit would further undermine his position.

It could be argued that Pompey are ripe for an upset. Russian owner Sacha Gaydamak is rumoured to be looking for a buyer for the club and several star players could be sold during the January transfer window.

Johnson admitted: "This is a game we can look forward to. No-one really expects us to win and all the pressure is going to be on Portsmouth.

"Portsmouth have a squad of 30 Premier League players and we're under no illusion about the size of the task before us. But we'll go there and give it a right go.

"There are upsets in the Cup every year and we have just as good a chance of causing one as anyone else."