Joe Morrell had to watch from the sidelines as Pompey’s play-off hopes faded away over the past few weeks.
The midfielder was serving a four-match ban after collecting his second red card of the season at MK Dons over Easter.
He was dismissed after the officials missed a clear foul on the Wales international, only to spot his reaction to it.
And Morrell accepts the criticism he has received for being absent during such a crucial stage of the season.
He said: “It’s been very frustrating, but I’ve only got myself to blame for that and you have to deal with the consequence of your actions.
“I’m more than happy to take the flak and the difficult thing has been watching these past few games and knowing that I could be making a difference. It’s been excruciating.
“I can have no complaints and have to take responsibility – it’s something that I’ve got to learn from. I apologised to the boys afterwards.
"I’ve got to get my head down, repay the faith people have shown in me and make sure this club is fighting at the top end of the table next season."
“I’ve always been an intense and aggressive player and don’t want to take that away from my game, but I’ve got to manage it correctly.
“So I’ve got to get my head down, repay the faith people have shown in me and make sure this club is fighting at the top end of the table next season.”
Pompey head to promotion-chasing Derby this weekend knowing that they cannot break into the top six.
Morrell said: “It’s disappointing that we don’t really have anything to play for with two games remaining.
“It’s not a position that any of us wanted to be in and we know the expectations of this club in this league.
“We know that anything short of the play-offs just isn’t good enough, while personally you can split my season in two halves.
“I probably came back a bit too early in the summer after playing for Wales and then picked up an injury, but you’ve seen a better version of me since the World Cup.”