Simpson was handed his first start since December against Metalist Kharkiv last week and the Salford-born defender produced a valiant display as part of the Magpies back four.
A lucrative offer is still on the table from Magpies chiefs, but until now the defender has refused to sign with the two camps' not seeing eye-to-eye over wages.
Mathieu Debuchy's arrival has also seen Simspon lose his right-back spot in Alan Pardew's starting XI, but with the Frenchman not in Newcastle's European squad, Simpson was handed his return in Ukraine last week.
It was also his first appearance since suffering a foot injury in the 7-3 defeat to Arsenal in December and despite talk of his future, Simpson has told his manager he can still rely on him.
"I'm a professional footballer and I'm a Newcastle player now," Simpson said. "There's three months to go and all I can do is train hard every day. I said to the manager whatever happens - injuries, suspension or whatever - he can rely on me if he does need me.
"That's all I can do, concentrate on training, and if I do get picked for the Europa League I've got to perform. Once the manager picks me and I'm on the pitch it's up to me to show what I can do. We'll just have to see in the summer what happens.
"It's been a tough few months but I've got a good relationship with the manager who knows my situation with the club.
"I'm the type of player who trains hard no matter what's going on. I think the manager might have seen that and maybe that's why he gave me the nod in Kharkiv.
"Hopefully I've staked a claim a little bit in this competition (in Kharkiv) or at least given him something to think about. It's massively important for me.
"It was good to repay him by playing my part in getting a win."
Newcastle sealed their place in the next round of the Europa League after Shola Ameobi's penalty gave them a 1-0 win over the Ukrainian side.
The result, though, was largely down to their stern resolve after coming under pressure from their hosts in the latter stages of last Thursday's match.
Simpson revealed the team had gone into the tie with a specific gameplan and he admits the side got it spot on in difficult surroundings.
He said: "We had a gameplan and it worked down to a tee. In the first 20 minutes we had a good spell. They were the home team so we had to deal with their pressure but I think just before the penalty we were starting to get into the game more and it looked like we were going to get a goal.
"Then in the last 20 minutes you have to dig deep and defend. That's what we did. If they did get through us, Tim stopped everything.
"Every away game in the Europa League is tough and away goals are massively important. We knew it was going to be tough because they're a good little team.
"But the gameplan worked and once we got the goal we knew we'd have to dig in deep and defend as a team, all 11 of us and the subs. It's a nice feeling to get through to the last 16."
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