Celtic have signed Scotland goalkeeper Craig Gordon on a two-year contract, with the option of a further 12 months.
The 31-year-old has not featured in a competitive game for more than two years because of a knee injury.
Capped 40 times, the former Hearts and Sunderland keeper will now join the Celtic squad at their pre-season training camp in Austria.
"I feel good, I feel ready to play. I want to play games. I hopefully still have a long career ahead," said Gordon.
"For me to be here at all is an achievement in itself so I want to make the most of it."
Fraser Forster has been Celtic's first choice goalkeeper for four years but has been linked with a move away from Glasgow. Understudy Lukasz Zaluska has a year of his deal to run.
Gordon made his debut for Hearts in 2002 before a £9m move to Sunderland five years later.
During his time with the Black Cats, he twice broke an arm and was recovering from a knee injury when he was released, having played his last match in April 2012.
He has spent the last two years working with physiotherapists to rebuild his fitness and trained with Rangers at the end of last season.
"It's been a long hard slog to get to this point, but it is a new challenge and a new beginning for me here at Celtic," he said.
"I need to work even harder to get appearances and get where I want to be.
"I would love to play for Scotland again, but I need to get back playing regular first-team games."