The Partick Thistle keeper joins up with the Northern Ireland squad in London ahead of their World Cup qualifiers against Slovakia and the Czech Republic in the coming week.
It's Tuffey's first call-up into the senior ranks and the 21-year old said he is "very excited" to be joining up with Nigel Worthington's team.
"The call came right out of the blue, I certainly wasn't expecting it," said Johnny.
"I was preparing to travel to Dundee for a game with Partick when the club secretary handed me an envelope on the bus from the IFA.
"The call-up is a massive surprise but I am very excited to be getting this chance.
"As good as it is for me I am also delighted for my parents who have been with me every step of my career and my coach Willie McKeown who has done so much for me."
Johnny joins up with the squad today (Tuesday) before jetting off to Bratislava tomorrow to prepare for the opening game in Northern Ireland's World Cup qualifying campaign. Then it will be back to Belfast to get ready for next Wednesday's showdown with the Czech Republic at Windsor Park.
It's unlikely Tuffy will make an appearance in either game but the Banbridge man is determined this is the start of something big for him.
"It's a long-shot that I will get a game but you never know what could happen between now and the games," he said.
determined
"I'm just pleased to be in the squad with two great keeper's like Maik Taylor and Alan Mannus and I am determined to learn as much from them as I can. I also want to learn from the players in the team who are playing at the highest level.
"I want to make sure I leave an impression because I don't want this call-up to a one hit wonder and I am determined to stake a claim for my place in the squad." Tuffey will be missing a Partick game but says he has the blessing of his manager and everyone at Thistle who are delighted for him.
Meanwhile, Banbridge lads Aaron Burns and Philip McGrath have been called into the Northern Ireland U17 squad for two friendly games in Sweden this week. The games are being used as a warm-up for the UEFA Championship qualifiers in September.