A 1-1 draw away to fourth-placed Armadale Thistle on Friday night saw both sides fall behind Syngenta and Whitburn, who have now sealed the top two spots with one game to go.
However, due to league reconstruction this summer, if Darvel are promoted to the Lowland League through the promotion play-offs, a chain of events going down the divisions will see the third-placed side from conference X also promoted.
Reviewing the match, Irvine said his side’s missed chances came to cost them.
“It was just one of those games,” he explained. “We missed four or five really good chances that we had to score. We had enough chances to win the game a couple of times over.
“The goal we lost was poor and it was a corner we didn’t deal with well enough. It really was just one of those nights where they were clinical with the chance they got.
“Armadale have been really good towards the end of the season and they were in with a shout of winning the league too, just like we were.”
Athletic face Bathgate Thistle on Saturday and have a two-point advantage over Armadale, who face a trip to Stoneyburn.
Irvine added: “With Darvel, we could still go up which is the goal for us now. If they can beat Tranent, we go up, but we need to focus on the game in front of us.
“We want to end the season with a win.”