It's just a case of if it happens next or if we fight (someone else) in the summer and then Wilder.
Parker can certainly take positives from the unification showdown, becoming the first fighter to take Joshua the scheduled distance in a professional contest.
"What you can not forget is I am the unified heavyweight champion of the world", Joshua said, as he pointed to the WBA, IBF, WBO and IBO world heavyweight titles, four sets of letters that run alongside his name.
Watford's world champion said: "2018 was always a time to capture all the belts". "We are one away now".
"We knew it was a big ask".
Not that the champ has let any of the criticism get to him - and he had a little message for those who felt they hadn't got the spectacle they wanted on Saturday night.
He said all the right things in the immediate aftermath; disappointed but determined to come back bigger and better, and in theory this experience in front of a partisan and in some cases unpleasant crowd of 78,000 should make him a better fighter.
"If they (Wilder's management) stepped up and were actually serious about the fight, and serious about a deal we are more than fair to offer them, it could happen next". Can I get a bonus now, do you know what I mean?
The British heavyweight star has added the WBO belt to his IBF and WBA "super" titles as he produced a disciplined display against the rugged Parker to earn a wide unanimous decision with scores of 118-110, 118-110 and 119-109.
FOR the first time, a unification title fight to bring together the WBA, IBF and WBO world heavyweight titles took place on British soil and last night (Saturday) Anthony Joshua came out the convincing points victor.
Parker loses for the first time in a 25 fight career.
Joshua was a worthy victor by scores of 118-110, 118-110 and 119-109 in boxing's first three-belt unification fight for seven years.
"I will get all five of the belts", Joshua said.
Despite immediately calling out Wilder and former champion Tyson Fury, Joshua's confident Parker will bounce back from the loss and they will meet again in the ring.
But he added in his later news conference: "If there was healthy offer [to fight in the U.S.] I will consider that".
The next few months will be crucial. "We will stay here", Joshua, 28, said in the ring post-fight.
It's the biggest fight in boxing at the moment, with the victor becoming the first four-belt world heavyweight champ.