Graham Potter has tweaked his attacking tactics of late and Leo Trossard has been used in a false nine role - a move that has seen Maupay drop to the bench.
Maupay started the season well and scored four from Albion's first six matches but his last goal arrived in the 1-1 draw at Crystal Palace back in September.
He then drew blanks against Arsenal, Norwich and City.
Maupay, 25, has been Brighton's most reliable scorer for the last three seasons and fans were surprised to see him left out and then introduced from the bench so late at Villa.
Potter's team enjoyed 69 per cent possession at Villa Park but lacked a cutting edge. Their best chances fell in the first half to Trossard and Tariq Lamptey who were both denied by decent saves from Villa stopper Martinez.
Maupay entered the action with just 10 minutes remaining but had little chance to make an impact. In fact it was Villa who made the most of the extra space in the closing stages with Ollie Watkins and Tyrone Mings firing them to victory.
"It is not about individuals," said Potter, when asked why Maupay was on the bench at Villa Park. "It is about how we do it as a collective.
"We gave ourselves a chance to do it but we didn't. We have to look at ourselves and try to improve that as a team and as a collective. Because it is not about individuals we have to do it together."
Potter's 'false nine' approach worked well at Liverpool and also in the first half against Newcastle. It allows extra bodies in midfield and helps Albion control possession and also gives licence for Lamptey and Marc Cucurella to attack from either flank.
Trossard was excellent at Anfield but at Villa the Belgian international struggled to make an impact.
"[Trossard in the false nine] was not so effective because we lost," Potter added. "Whatever you do is less effective when you don't win.
"We have to look at how we attack. Of course Neal Maupay is in contention [for Leeds] because he is an important player for us, as are all our players.
"We have to be disappointed today and train this week and be sharp.
"It is nice to think one person fixes all the problems and provide the solution but that is not the case.
"It would be unfair on anybody to put them in that position. We have too do better as a team."