Sam Johnstone has experienced enough of football's highs and lows to understand that joining Celtic was never likely to be a straightforward undertaking.

But despite a turbulent introduction to life in Glasgow, the Wolves loanee insists he has absolutely no regrets about taking on one of the most demanding challenges of his career to date.

The former England international headed north of the border earlier this summer in search of regular first-team football and a fresh challenge. What followed has been a mixed introduction, with inconsistent results bringing added scrutiny, while adapting to a new team environment has required patience.

His career has been defined as much by patience as it has by perseverance. The Manchester United youth product has spent lengthy spells waiting in the wings for his opportunity, often occupying a back-up or third-choice role, while striving to establish himself as a No.1

Arriving at Celtic has offered a welcome change of circumstances. Rather than being confined to a supporting role, Johnstone has the chance to make the position between the sticks his own as he continues to enjoy a sustained run of games and remind people of the qualities that once earned him international recognition.

There is also the matter of developing relationships with the defenders in front of him. Communication, trust and familiarity are essential for any goalkeeper, and Johnstone recognises that those connections take time to establish.

“I think I've got to get used to them, they've got to get used to me, and that only happens through playing and through games. It's great to be in the team,” he said. “To get a run of games for any player, you find your rhythm. It was a new club for me, a new team, so that takes probably a couple of games to get used to as well.”

Celtic squad morale affected by fluctuating results

Having represented established clubs such as West Bromwich Albion and Crystal Palace, Johnstone is no stranger to pressure. However, he has discovered that the expectations at Celtic are particularly intense, arguably unlike anything he has experienced elsewhere in his career.

“Of course it has,” Johnstone admitted when asked whether fluctuating results had affected the mood within the dressing room. “I think the results affect it. This club's not used to losing, and we've probably lost too many games for this club.

“The expectation here, rightly so, is to win. Unfortunately, we hadn't quite met that expectation, and the lads know that. We all realise that, but we have to put things right in each game. It was tough. We're honest players, we're honest people, and honest with each other.”

Ultimately, though, signing for Celtic was an opportunity Johnstone was never likely to pass up. The quality within Martin O’Neill’s squad, coupled with the passion of the supporters and the chance to experience the club's unique atmosphere, made the move an attractive proposition.

“It's brilliant to play for this club,” he insisted. “The passion of the fans, good and bad. The standard of players on the pitch, day in, day out at training. When I came, I said I didn't have to think twice about coming here. It’s a great team to play in. The lads came up with the goods (on Thursday vs Besiktas], so we keep taking it game by game and go again on Sunday.”

Whether his time with the Scottish champions will provide the springboard to revitalise his career remains to be seen. Asked if the move had given him a fresh lease of life, Johnstone was typically measured in his response. “Let's see, let's see.”