Wednesday's skipper was a rock against Brentford in the semi-final clash and his leadership has been key to the club's success this campaign.
But no players have yet been offered deals and with the Scotsman being 34 and knowing that his family are waiting for him north of the border, it will be a difficult decision to make.
"It's been a really difficult one for me and I don't think I've made my mind up - but maybe the club have already made up theirs," Bullen told the PA.
"It comes down to the club's finances. It's difficult, but at the moment it's looking like it could be my last game for the club."
Onto Sunday's clash with Hartlepool, Bullen knows that the fans will play a pivotal role if they back the team like they did in the semi final.
He added: "Throughout the season, whenever mistakes were made, goals given away and slack passes you could sense the crowd grumbling and that affected the players.
"But against Brentford the crowd raised the decibels and got behind the team and it makes a crucial difference. It inspired us."
Wednesday will be without long-term injury absentees Adam Proudlock, Steve MacLean and Graeme Lee, who is out of contract this summer, along with Bullen and Matt Hamshaw.
Richard Wood and Drew Talbot have come through illness and will be fit for Sunday, while James Quinn missed a day trip to Rother Valley so he could rest a slight niggle but will be fine for Sunday.
COME ON WEDNESDAY - BRING US SOME GLORY!