The former Manchester United defender, whose sole first-team action was the opening 45 minutes of their 4-0 League Cup defeat to MK Dons last season, signed a four-year deal on Wednesday and later watched his new team-mates beat Dutch side Den Bosch 2-0 in a friendly at St Mirren Park.
He failed to make a senior league appearance for Louis van Gaal’s side but did play 10 times under former Celtic boss Neil Lennon while on loan at Sky Bet Championship side Bolton last season.
“I signed here for four years and I want to do my best,” said the 19-year-old. “I hope I can please the fans with my performances.
“I am a Celtic player, my head is here at Celtic and I am not looking to go anywhere in a few years time.”
Janko also hopes the chance of more regular playing time will help his bid to secure a place in Switzerland’s national team, and he is particularly excited about the chance of making his Champions League debut.
Celtic kick off their 2015-16 season with a European double-header, taking on Icelandic side UMF Stjarnan in the second round of qualifying for this year’s competition.
He told Celtic’s official website: “The move went quite smoothly, there was no hassle or anything so it was okay and I’m happy that the medical is over and I’ve signed a four-year deal.
“I’m looking forward to teaming up with my new team-mates and to the new challenge. Obviously Celtic are a huge club and I just want to get playing.
“Hopefully I’ll get as many games and as many trophies with the club as possible. I want to play in the Champions League and play international football, because with Celtic that is possible.”
And the teenager, who began his youth career with FC Zurich as a 14-year-old, is looking forward to Champions League nights at Celtic Park after reading of the atmosphere generated by a number of the world’s top players.
Former Barcelona skipper Xavi, who has played at the ground a number of times, said: “The stadium is a marvel. The fans, the people, how they support their team, It’s an example for every team,” while AC Milan legend Paolo Maldini said: “Every professional footballer should seek to play at least one game at Celtic Park. I have never felt anything like it.”
Lionel Messi, Andres Iniesta and Cristiano Ronaldo has been equally praiseworthy and Janko said he could not resist the move north after listening to the footballing icons.
“I’m looking forward to the atmosphere and the fans hopefully on a Champions League night or even league days,” he said. “Even players like Messi and Xavi dream about the atmosphere at Celtic Park so I’m looking forward to that.
“I was quite happy to stay at Manchester United but Celtic is hard to resist. I’m in the first team every day I’ll train with them and hopefully get in the first XI. At Man United it’s a bit more difficult.
“Celtic is a massive club in Europe. I think all over the world people know Celtic, people know the supporters. They have a big stadium too, it’s huge.The Champions League is every kid’s dream and it is definitely a plus I think.”