But first comes Latics' derby with Bolton Wanderers on Sunday when they'll be hoping to stretch their unbeaten league run to five games.
McCulloch said: "The Bolton game is a massive one for us and if we can get all the three points that would be fantastic.
"What would be ideal for me this season is us staying in the Premiership and then going to the World Cup with Scotland.
"Wigan, though, is my number one priority and I would even miss the World Cup if that meant we were still a Premiership side next year.
"I'm pleased to be back in the Scotland squad again because I was ruled out of the last two internationals with a knee injury.
"Walter Smith phoned me when I was injured to check how I was and see how the knee was progressing, so that was a boost.
"We can get in the play-offs for the World Cup if we beat Belarus and Solvenia, and Norway drop points.
Injections
"They will be tough games, but the boys will be full of confidence after our previous good results."
McCulloch is still needing pain-killing injections to get through games at the moment, although that shouldn't stop him joining up with Scotland after the Bolton clash.
Manager Paul Jewell joked this week that the jabs were just for effect, but the
midfielder insists they are necessary.
The medial ligament injury in his knee which McCulloch picked up in pre-season is causing the problem.
He said: "The injury is a complete pain.
"I'm running fine but striking the ball is still the problem and I've really got to wait for it to settle down and go away.
"I've seen two specialists about it, one of whom is said to be the best in Britain when it comes to this sort of injury.
"He recommended the pain-killing injections and I've been having them before the matches to get through.
"I think the ligament is just twisted and something must be hitting a nerve, although I've been assured I don't need an operation.
"Our physios Alex Cribley and Alan Tomlinson have been absolutely first class, getting me appointments with these specialists at the drop of a hat and keeping me training.
"The injury will settle down in time, although at the moment they can't put any length of time on it so I'll just have to be patient."
McCulloch predicts a tough test against Bolton on Sunday (1pm) as Latics look to build on last week's away win at Everton.
"They are on a really good run at the moment and are a strong, physical team," said the 27-year-old.
"We're going to have to match them all over the park and if we do that, hopefully we can get a result."
McCulloch is one of six Latics players likely to be away on international duty following Sunday's game.
David Connolly has got his first call to the Republic of Ireland squad for two years, joining Graham Kavanagh for the games against Switzerland and Cyprus.
Henri Camara is off to play for Senegal against Mali in an African Nations Cup qualifier, while England Under-21s are expected to select Leighton Baines for the matches with Austria and Poland.
Josip Skoko completes the call-ups for Australia's friendly with Jamaica a week on Sunday at Fulham's Craven Cottage.