The image, sent by Murphy via popular social network Snapchat, shows Murphy's face with the caption: "We are going to lose...Again".
It is unknown which game Murphy was referring, but the picture has caused a stir as it appears to mock Blackpool's plight in the Championship.
Lee Clark's men are currently rock bottom of the division, nine points adrift of safety with just two wins from their 24 matches thus far.
After the picture had surfaced on social media Murphy, who is on-loan from fellow Championship outfit Norwich City, issued an apology.
"I'd like to offer my sincerest apologies to the manager, my team-mates, the fans and everybody at Blackpool football club for the hurt and embarrassment that a recent photo message I sent has caused," he said.
"It was totally unprofessional of me and a foolish thing to do.
"I have loved my time at Blackpool so far, and I've been really grateful for the support I've received. I know I have let the manager and fans down badly, but I aim to repay them by working even harder and helping the team climb up the league table.
"I'd also like to make clear that Donervon Daniels [also pictured] had no part in this and I apologise for implicating him."
Clark added: "I'm extremely disappointed because I expect nothing but total professionalism from my players. We will now investigate this matter internally before deciding upon an outcome."
Blackpool drew 1-1 against Rotherham United on Sunday, having lost 1-0 at Sheffield Wednesday on Boxing Day.
