The Brazilians have performed well below par since the start of the new campaign, winning one and losing two of their opening three PSL encounters, while their last match, a 2-1 loss at home to Maritzburg United, was further marred by misbehaving spectators demanding the release of head coach Johan Neeskens.
However, Modise is adamant the Dutch tactician is not solely to blame for the team's poor run, and told Football411 it is high time the squad members pull up their socks.
"I think players must play their hearts out. We must play as if it is our last game," Modise stated.
"It is pointless to see a situation where there are changes in the technical team. Coaches are getting fired because players are not performing the way they are supposed to so it is time players take responsibility.
"The coach is disappointed... We are disappointed. The coach spoke recently about a lack of commitment from the players and I understand because he sees committed players at training during the week and something different during a game, so we have to change this," he said.
Sundowns have gone four seasons without winning a trophy, and saw their 2012 MTN8 run come to an end at the semi-finals, and Modise firmly believes it is now or never for the Tshwane outfit.
"We are under pressure to win something this season. We can't run away from that responsibility and we spoke about it as players and we are all disappointed so we know what to do," he added.
"But the positive is that I can say that at least this has been happening now at the beginning of the season, unlike at the end. So what we lack is confidence and we have time to fix this before it is too late."