As the Latics immediately returned to training following their stunning victory over Manchester City at Wembley, results in the Barclays Premier League pushed them to the brink of relegation.
Their fate is still in their own hands as victories over Arsenal and Aston Villa will complete a dramatic escape and the most remarkable week in the club's history - but the task is a formidable one.
Anything less than victory against the Champions League-chasing Gunners at the Emirates Stadium on Tuesday will effectively end their eight-year stay in the Premier League. The Latics are four points from safety with a far inferior goal difference to their closest rivals Sunderland.
The situation means Wigan's sensational Wembley success - the biggest cup final upset for a generation - could quickly become one of the least savoured.
Midfielder Shaun Maloney, who was outstanding against City, said: "We are going to have to sleep well, we have got a big game on Tuesday.
"It is an incredible achievement to win the FA Cup and we are going to be on a pretty big high but the work for Arsenal has already started."
Wigan were rank outsiders against the odds-on City but were the more energetic and creative team throughout and thoroughly deserved the victory secured by Ben Watson's late header.
Maloney felt the team's ability to shut out their league travails, and a desperately disappointing loss to Swansea last Tuesday, helped them.
The 30-year-old said: "We forgot about the league and completely concentrated on the cup.
"We were massive underdogs and felt relaxed about it. That helped and it was enjoyable."
Wigan now need to use the adrenaline from Saturday to propel them to victory at Arsenal and set up a final-day showdown with relegation rivals and Maloney's former club Aston Villa.
Maloney himself is in fine form and has impressed throughout the season, fully justifying manager Roberto Martinez's decision to bring him back to English football from Celtic two years ago.
Maloney said: "I think I had to prove it to myself when I came down here.
"The manager and the club took a bit of a gamble after the previous couple of seasons at Celtic - I hadn't played a lot through injury.
"I appreciated the manager taking the time to speak to me and sign me. I think he needs to take the majority of the credit.
"I think this is probably the best I've played at this level on a regular basis.
"It has certainly been the most consistent over a season that I have played, and Saturday was one of the highlights.
"Hopefully there will be another couple of highlights over the next week as well."