Mittagong coach Graham Isedale makes no secret of his team's do-or-die approach to this Sunday's meeting with Wests.
The Lions are fifth on the ladder, two points adrift of fourth-placed Robertson with four rounds remaining.
A win over Wests would significantly boost their prospects of a top-four finish.
"It'll probably be the end of our season if we don't win this week," Isedale said.
After Wests this weekend, Mittagong takes on Robertson, Albion Park and Dapto.
The Lions scored a 1-0 win over Wests in round 13.
"They're a quality team," Isedale said.
"We did beat them last time when they were under strength but both teams at full strength is a really good game and we know we can beat them.
"Their short corners always cause problems for us. When we lose to them, they always seem to score two or three a game so the key for us is to stop them getting those short corners."
Isedale said his side wasn't short on belief.
"The guys are all very keen to grab a spot in the semis," he said.
"These next couple of games are our season. We need to beat Robertson and Dapto as well. That'll make us close but we still might need a couple of results to fall our way."
Mittagong lost 8-1 to University last week, while Wests won 5-0 over Dapto.
Sunday's match of the round is a top-of-the-table clash between favourites University and Albion Park.
Uni player-coach Heath Ogilvie predicted a "free-flowing game with plenty of goals". Robertson square off with Dapto in the other round-18 game.
In other hockey news, Lake Heights teenager Max Hughes was selected in the Australian Hockey 5s (five-a-side) Youth Team for a tour of China.
The team - four players and a goalkeeper - will contest next month's Nanjing Youth Olympic Games.