The Republic of Ireland international opened the scoring for the Magpies second string, heading in Massadio Haidara's cross just before half time in the 1-1 draw with West Bromwich Albion at Whitley Park.
It was the 33-year-old's first outing since the 2-0 EFL Cup win over Wolverhampton Wanderers in September.
A calf problem has sidelined him since then but having made his return for Peter Beardsley's side, Murphy says he's hoping to continue his progress in the coming weeks as he looks to battle his way back into contention for Rafa Benitez's Sky Bet Championship table-toppers.
"I'm getting there, slowly but surely," he told nufc.co.uk. "I've been back in training for a few weeks now which is obviously good for me, but I think it's game time that gets you that extra bit of sharpness and thankfully I had that on Monday.
"I'll just keep training and hopefully catch the manager's eye.
"I'm a striker and I want to score goals. The most important thing was just to get minutes under my belt and make sure that injury-wise I'm alright, but the goal was a bonus.
"I've been itching to go since I got injured, and watching the games isn't nice. The lads are on a brilliant run and everyone's playing well, so I need to impress to try and force my way in.
"I can't wait. I was just happy to get through it to be honest, and I felt no niggles or anything like that so that's a plus."
The former Ipswich Town forward added: "It's probably the most frustrated I've been in my career to be honest. I've never been out for this long so it's all new to me, and watching the lads play week-in, week-out from the stands is not very nice.
"But I'm back training, I've just got 45 minutes under my belt so hopefully it'll stand me in good stead."
Murphy - who was withdrawn at the break - was one of three first teamers who were handed run-outs for the Magpies Under-23s side against the Baggies, with Haidara and Achraf Lazaar playing the full 90 minutes.
And the frontman spoke highly of the youngsters coming through the United ranks after helping them extend their unbeaten run to four games.
"I was impressed. I thought they played really good football, which was refreshing," said Murphy. "We played out from the back, and we created a few chances on Monday. We were unfortunate to finishing one-all, and we're not happy with that.
"You always know at 1-0 it's not a great scoreline. If we had nicked the second it's maybe a different story, but we gave them the chance to get back into the game and they did."