Ronnie Deila's first signing has spent the last two years in the football freezer after injury saw his career hit the buffers.
But the former Scotland keeper got 45 minutes under his belt during last Saturday's friendly clash against Dynamo Dresden.
And he hopes that game will be the first step to reviving his career - and challenging Fraser Forster in a battle for the Parkhead gloves.
Forster earned his pay with a string of lively saves against Dresden in a 1-1 draw.
He was replaced at half-time by Lukasz Zaluska, but was happy to look back on a confidence-building clean sheet in the first 45 minutes. The former Hearts and Sunderland stopper told The Celtic View: "It was good to get back playing.
"From a personal point of view, it's been a long time out.
"So it was good to get out there and to play for 45 minutes and get a clean sheet in the first half. I have to be happy with that.
"I knew coming in that there would be two teams playing each half and that I would be playing in the first half so it was good to get myself ready for that.
"It's a good step in the right direction and hopefully before too long I will be ready for more
"They probably edged the chances in the first half and missed the target a couple of times when they probably should have done better.
"We were maybe a bit fortunate to come in at the break without conceding but it was pleasing from my point of view to come in without losing a goal."
Meanwhile, kick-off time changes have been made for two of Celtic's SPFL games in September, one at home and one away.
The home match against Aberdeen on Saturday, September 13, will now kick off at the earlier time of 12.45pm.
Similarly, the away game against St Mirren in Paisley on Saturday, September 27 will also kick-off at 12.45pm.
lDerk Boerrigter was on target as a Celtic XI ran out 3-0 winners over Morton in a closed-doors match at Lennoxtown. Celtic's other goals came from Liam Henderson and Paul McMullan.