The goalkeeper jetted into Austria to meet up with his new team-mates late on Thursday and took part in his first official training session yesterday.
Although Gordon missed out on the victory over FK Krasnodar that didn't stop the experienced keeper going straight to work with goalkeeping coach Stevie Woods.
Gordon told the official Celtic website: "I'm settling in well. I got my first training session under my belt and it was a good, tough session, so I'm happy to just get here and get started.
"Stevie Woods works the goalkeepers very hard and that was a tough session here, but that's why I'm here, to try and prove myself and get back to where I was and then improve on that.
"It's a good relationship and we will work to where we want to be.
"The set-up here has been good from what I've seen so far. I got here in the early hours of yesterday morning so I've not had much time to have a look around yet but, the training pitch was a good standard."