Ryan Williams insists there can be no excuses after Pompey failed to secure their place in the League One play-offs.
A home defeat to Accrington cost them the chance to battle it out for the final spot in next season’s Championship.
Instead they finished in eighth position and must now prepare for a fifth successive campaign in the third tier.
But Williams knows there were no hard luck stories and the Blues ultimately finished where they deserved.
He said: “We gave ourselves a mountain to climb and shouldn’t have left it until the final day of the season.
“There have been chances to win more games and haven’t taken them, so we’ve only got ourselves to blame.
"The good periods this season have been really good, but the bad periods have been really bad."
“We couldn’t find our rhythm or be able to string good passes together, which has been a key factor when we’ve done well.
“The good periods this season have been really good, but the bad periods have been really bad. Inconsistency has cost us.
“We didn’t defend our box well enough or take our chances when it really mattered – and everyone has to hold their hands up to that.
“It wasn’t enough and we didn’t do what we needed to do. It’s completely and utterly our fault for that.”
Williams’ contract is expiring this summer and the Australian forward does not know if he will be remaining on the south coast.
He said: “I haven’t had the conversation with the club yet, but everyone knows I want to stay, so I’ll have to wait and see.”