King will be jailed for 18 months after being found guilty of sexual assault and actual bodily harm over an incident in a London nightclub, which occurred in December while he was on loan at Hull City.
Wigan chairman Dave Whelan later confirmed King will never play for the club again but the player's agent, Tony Finnegan, says plans for appeals are in place.
"No-one saw this coming in light of the evidence. He's very, very disappointed - because clearly, as he said in his evidence, it's mistaken identity. He didn't do that," said Finnegan.
"He'll be devastated, sitting in a cell with someone tonight. But he's a grown man; he's been there before and he'll take it on the chin.
"No-one expected this. I asked Marlon and he said, 'I'm not guilty, Tony - I didn't do it. I want the British justice system to find me not guilty'."
DisappointmentFinnegan expressed disappointment at Wigan's decision and the failure of the Professional Footballers' Association to support King, before questioning what might happen if the striker is released early.
"There was a union that didn't seem to back him in the shape of Bobby Barnes this afternoon and the chairman of a professional football club that is going to say to everybody throughout Britain that this man will never play football again," he added.
"The chairman's got a choice. If the chairman, which is his right, decides to sack Marlon King under gross misconduct, he would have to put that in writing, first and foremost.
"Then he has a right of appeal to the Premier League, in writing.
"While the appeal process goes in, which will be on Monday, this lad could be out in two, three weeks, four weeks; then those bail conditions will be subject to him being in his house.
"If Wigan aren't successful in sacking this player and he comes out in three months' time and he wanted to be signed by another Premiership club, do Wigan allow him to go for nothing or do they seek a fee?"