Portsmouth have bounced back brilliantly from their 4-0 defeat at home to Blackpool with back-to-back wins away from home and two clean sheets.
John Mousinho’s side were being doubted after a draw at home to Charlton Athletic and the Blackpool result, but the last two wins have again put them on the perch of the League One standings.
However, a real test lies next Monday night when they will host Bolton at home and Clarke believes that will be the acid test for Mousinho’s team.
The former Championship star pointed out that Bolton, who are second in the League One standings, are scoring for fun at the moment and have also shown that they can grind out results when needed.
Clarke said on the What The EFL Podcast: “Yes, we will see where they are at.
“Bolton are scoring goals for fun at the moment, even in the FA Cup at the weekend and absolutely battered Harrogate.
“They are really in hot form.
“Went to Oxford in a really tricky game and showed the other side of Bolton to ground out a 0-0.
“This will be the acid test for Pompey.”
Portsmouth could open up a six-point gap at the top of the table if they beat Bolton next Monday night and boost their hopes of winning promotion.