Portsmouth's FA Cup semi-final victory over Tottenham at Wembley on Sunday means a seventh-place finish in the Premier League should secure a Europa League third qualifying round berth in 2010/11.
That is because administration-hit Pompey chose not to apply for a UEFA club licence for next season. The South Coast club is planning a retrospective application, although that may not be sanctioned - giving Everton renewed hope of claiming European football via their league position.
However, the issue could be complicated further if Fulham win this season's Europa League. The Cottagers would be asked to defend their title as holders, in which case the team finishing seventh in the Premier League would probably miss out.
In addition, England may gain an extra Europa League representative if the country is ranked in the top three positions in UEFA's Fair Play table for this season. England was in third place at the turn of the year; Fulham would appear the most likely beneficiaries if this route through to the first qualifying round became available.
As for the race to qualify via the Premier League, Everton are currently eighth, four points behind Villa having played a game more than Martin O'Neill's side.
The odds still favour the Birmingham club but with the two sides set to meet at Villa Park on Wednesday night, Moyes and his men have everything to play for.
"The Aston Villa game will decide an awful lot," admitted Moyes, whose Toffees have five league fixtures remaining this season.
"If we win four and lose one, I don't know if that will be enough to get us into Europe, but who knows? It might well do, depending on the other games.
"But we've got hard games, Blackburn are very good at home, Stoke are a great side at home as well, so we know we've got a tough run-in without playing many of the teams at the top end of the league."
Moyes, who recently picked up the Barclays Manager of the Month award for March, has also talked about his quest to one day bring silverware to Goodison.
"I'm desperately ambitious and one of the things I haven't been able to do at Everton is win a trophy," he said.
"I'm desperate to try and win something, to give the supporters something.
"Maybe qualifying for the Champions League three of four years ago is the equivalent of winning something.
"I think our team is good enough to be competing for fourth. Would we have made it? I don't know.
"But I think we're good enough to compete with the group of players we've got," he added to the Daily Post.