The batsman had not been selected since December 2016 and had largely been known for playing limited overs cricket in recent months
Jos Buttler excited by 'incredible opportunity' of Test recall by England for Pakistan series
Jos Buttler admits his England Test recall "feels like another debut" after almost 18 months out of the side.
Buttler played the last of his 18 Tests in December 2016, against India in Chennai, and has largely focused on his white-ball game since.
He has remained an integral part of England's limited-overs set-up and has taken this year's Indian Premier League by storm with Rajasthan Royals - but was still shocked to get the nod to face Pakistan at Lord's this week for the first Test, which begins on Thursday.
"It's a fantastic surprise and an incredible opportunity afforded to me," he said during a news conference.
"Any time you turn up here at Lord's it's special, and all of those emotions are arriving today. It feels like another debut really. It wasn't particularly on my radar."
Buttler had considered the idea he may never get the chance to wear the England whites again - but despite his globe-trotting Twenty20 exploits, never gave up hope of challenging himself in the five-day version of the international game again.
"You always think maybe that race is run and will never happen again," he added. "It's not that you live with regrets but you definitely miss it.
"To get that call, the overriding emotion was excitement ... I came for a hit here on Saturday. Turning up here on England duty to play a Test match is unbelievable."
Buttler's IPL stint means he has not played a first-class innings since turning out for Lancashire against Essex last September.
But he plans to play with a similar - though not identical - freedom that he brings to the short formats.
There were suspicions that he was too reticent, and too eager to prove he had a workable five-day game, on his previous Test appearances.
But with Joe Root as captain and a new national selector in Ed Smith, the tone appears to have shifted and space has been made for him in the side, with Jonny Bairstow, who will keep wicket, set to move up the order to No 5.
"It's going to be a challenge," said Buttler.
"But from the conversations I've had with Joe and Ed Smith, it's very much that they want me to play the way that suits me and in the fashion they believe will get the best out of me in that number seven role.
"For me it's about expressing myself, trusting my instincts and allowing that to flourish rather than fight it.
"I'm pretty sure I won't be opening, trying to slog it in the first six overs but hopefully I can entertain."