The England star signed for Delhi Daredevils last week as an 11th-hour replacement for the injured South African pace bowler Kagiso Rabada.
Plunkett will miss the first five County Championship games and up to as many fixtures in the 50-over Cup.
But he said that he had no plans to follow the white-ball path lately travelled by England team-mates Adil Rashid and Alex Hales, both of whom have opted out of red-ball cricket.
“Test cricket is the pinnacle of everything for me,” said Plunkett, who made the last of his 13 Test appearances against India at Lord’s in 2014. “If it happens again, great, although I’m not really thinking about it at the moment.
“I’m looking forward to playing more Championship cricket going forward and doing my best to win games for Yorkshire.
“I enjoy playing Championship cricket and, if that came again (Test cricket), happy days.”
Plunkett, 33, believes Yorkshire will be a force in this year’s tournament.
The club are looking to bounce back from a disappointing 2017, when they were somewhat flattered by a fourth-placed finish.
“Last year we didn’t play our best cricket, and this year we know we need to improve,” he said.
“But it’s the fittest group of lads I’ve ever trained with, and we had a good pre-season tour in Potch (Potchefstroom, South Africa).
“Last year humbled some of our lads, but we know how to win the Championship, having done it before.
“It’s going to be tough, especially playing for a big county because everyone wants to take you down, but we’ve got an excellent squad.”
Looking further ahead, Plunkett is relishing the prospect of next year’s 50-over World Cup.
“The prospect of that (playing in the tournament) is massive, but there’s a lot of cricket ahead and you’ve still got to perform and improve if you want to be in the mix,” he said.
“It’s enjoyable; people know their roles and everyone wants each other to do well.
“We’ll be one of the favourites, but we were one of the favourites last year in the ICC Trophy and that didn’t happen, so you can’t take anything for granted.
“You can play amazing cricket at the start of a tournament and get knocked out later, so you’ve got to be switched on all the time.”