The 30-year-old central defender has burst back on to the Premier League scene in recent weeks, scoring in the Magpies' victories over West Ham and Bournemouth to cap impressive individual performances after having to remain patient.
However, he has revealed he might not have been around to do so had new head coach Steve Bruce not wanted to have a look at all the players he had inherited from predecessor Rafael Benitez.
Asked if he had considered a move away from Tyneside after limited opportunities, Clark said: "Yes, definitely. "It was something I was thinking about in the summer. I didn't know what the situation would be at club level with the manager and I'd thought about that a lot.
"Steve came in late into pre-season and there wasn't much time then to do anything, really, I guess and looking at it, he obviously wanted a chance to look at everyone that he had in the squad.
"I had a chat with him and I said, 'This season, I'd love to be playing games because I've had a couple of years now where I'm in the team and out of the team and it's a bit hit and miss'.
"He understood that and said, 'Look we'll see how the first part of the season goes and we'll re-assess that come January'.
"He was really fair with me and then it was down to me to just keep training hard and working hard and seeing what would happen."
Clark's form has been such that he has won a recall to the Republic of Ireland squad and will start Thursday night's friendly against New Zealand in Dublin, giving him a chance to catch manager Mick McCarthy's eye once again ahead on Monday's final Euro 2020 qualifier against Denmark.
He has not played for his country since a 4-1 Nations League defeat in Wales in September last year and is relishing the opportunity to pull on the green shirt once again after admitting his frustration at not making the squad.
He said: "It's hard, but that's just football, you know? If you're not playing games regularly, then it's hard to justify being picked.
"It's frustrating and disappointing, but it gives you that motivation to keep working hard day in, day out and trying to force your way back into it at club level to then to try to get into the squads."