And the Gillingham boss insisted his side beating Danny Cowley’s men at Priestfield will be the upset of the weekend.
Evans has thrown the weight of expectation on to his opponents this weekend, with the Scot missing a stack of players through injury.
Pompey go to Kent in powerful form after winning five games on the spin and remaining unbeaten in eight.
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Cowley found himself under pressure not too long ago as his side struggled, but Evans felt the Londoner was also going to turn things around as he complimented the players at his disposal.
Evans told Kent Online: ‘They are in brilliant form under Danny Cowley and they know they are getting to play us at the best time.
‘These teams are getting their Christmas early when they are playing us at the moment, but we will remain disciplined, we will keep fighting.
‘It will be the biggest upset of Saturday afternoon’s results if we can beat Portsmouth, that’s for sure.
‘They were always going to start winning games.
‘I think when people saw them getting beat, losing and drawing games, people questioned Danny Cowley’s future.
‘That was a surprise to all of us because you look at the squad he has got but he has got them going now, it will be a real tough game for us.’
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