Defender pinpoints Portsmouth toughest rivals

And the defender felt his side were '˜lucky' to emerge with a 1-0 victory as they got off to a winning start against Luton on the opening day.

So, like all people associated with Pompey, Clarke was an interested observer as manager Nathan Jones departed one of his outfit's prime promotion rivals for Stoke this week.

Luton's outstanding form this term, which sees them on a run of one league loss in 19 after securing promotion, prompted that exit.

Although perhaps not one of the most fashionable clubs, Clarke has no doubt of the threat they possess to Pompey's promotion ambitions.

He said: '˜They are one of the teams where people ask how are they doing so well?

'˜But when you play them you realise they are a very good side.

'˜They have good players and a good style which is working for them

'˜It's no surprise they're doing so well after you've played them because they play some good stuff.

'˜You look back at the games and that is the one where you say we got away with one.

'˜They dominated most of the game, had chances and hit the post. We got a bit lucky with that on that day.

'˜We got a bit lucky and I'd definitely say they are (the best team Pompey have faced).

'˜Sunderland at times had quality but going down to 10 men hindered them.

'˜Luton are definitely up there for the best side we've played.'

The wait now goes on to see who will be named as Jones' successor with the likes of former Pompey boss Michael Appleton being touted for the position.

Clarke sees the upheaval at Kenilworth Road having an impact, although it remains to be seen if that's positive or negative.

'˜I guess it will have some sort of effect,' he added.

'˜They've had a settled platform for three years and they've found a style which has worked for them.

'˜They are on a great run of form so the change will have some sort of impact.

'˜Sometimes when you get a new manager in there's a spike and there's a positive effect.

'˜We'll have to wait and see.

'˜The most important thing is we concentrate on ourselves and when the Luton game comes around we treat it as any other game.'

Luton may be the team who've impressed Clarke most, but the contenders for Pompey's place at the top of the table goes far beyond the Hatters in the 22-year-old's eyes.

Clarke said: '˜It looks like us, Luton and Sunderland now but it can change very quickly.

'˜No one's writing Barnsley, Charlton, Doncaster or any of them off.

'˜You know what the league is like. You can go on a mad winning run and pick up a lot of points.

'˜People come out of nowhere, so it's definitely still an open field.'