The Republic of Ireland striker was hauled out of cold storage this week and handed a first start since Boxing Day as boss Neil Lennon went direct on St Johnstone's shocking pitch.
Murphy didn't let his manager down and played a key role as the leaders cemented their position at the summit with a crucial 1-0 win.
The former Sunderland forward said: "If I end up scoring the winning goal that clinches the league title it will be unbelievable because I've not played a lot and I've not scored many.
"I want to get into the team and try to score some goals before the end of the season. That would make up for missing so many games because that is what the fans want to see from me.
"I always knew it was going to be hard when I joined Celtic. It wasn't just a case of turning up here. With the players the manager has brought to the club I could see how hard it was going to be.
"It was about getting my head down and seeing what happened but it's been tough. I've had injuries at the wrong times and the two lads who have come into the side have banged in goals.
"It was always going to be hard to get back into the side. When you look at the two lads and the fact they are scoring goals, you can't be disappointed that you're not picked. That's the way it goes.
"You just get on with it, train hard and see what you can do if you get picked."