Sam Johnstone's Impressive Celtic League Debut

Sam Johnstone walked off McDiarmid Park grinning, the kind of grin that tells you a week has just flipped on its head.

"Amazing. What a feeling," he said, and it looked it.

Twenty-one months since his last league appearance. A late-window move from Wolves. Dropped straight into a tight, tense away game as Celtic clung on to their perfect start with a 1-0 win over St Johnstone. This was not a gentle reintroduction. It was a test.

Surprise start, emphatic answer

His name on the teamsheet raised eyebrows. Viljami Sinisalo has been assured, steady, exactly what Martin O'Neill wants behind a dominant side. Instead, out came the 33-year-old England international, four caps to his name but short on recent club minutes, to make his Celtic league debut in Perth.

If there were any doubts in the stands, they didn’t last long.

Johnstone made three saves, all from efforts inside the box, as St Johnstone threatened to puncture Celtic’s 100% start. The standout was a moment that will live in his early Celtic scrapbook: Joel Cotterill met a cutback with a crisp first-time strike, the ball flying goalward, only for Johnstone to explode upwards and tip it over with a brilliant, instinctive reaction.

It was the sort of stop that changes games and, sometimes, careers at a new club.

He commanded his area when called upon, winning his only aerial duel and punching clear under pressure. With the ball at his feet, he looked comfortable too, completing 31 of 38 passes and launching five of them into the final third to turn defence into attack. Late on, cramp nipped at his legs, a reminder of that long wait for league football, but it didn’t loosen his grip on the clean sheet.

"It's been a rollercoaster week, coming in and getting to know the lads and staff, training and watching a couple of games," Johnstone said afterwards.

"So to finally get on the pitch and get a win, clean sheet, play in front of the fans, it was an unbelievable feeling. I'm really happy."

O'Neill's dilemma before Ibrox

Johnstone’s performance has done more than protect Celtic’s record. It has complicated O'Neill’s plans for Sunday.

The League Cup quarter-final at Ibrox looms. Rangers away. No room for sentiment, no room for experiments. Yet the manager has just watched his new goalkeeper deliver exactly the sort of debut that forces a rethink.

"The save was fantastic, a really, really brilliant reaction save," O'Neill said.

"He's a fine goalkeeper and it's just a matter of him getting up to speed with things. Sinisalo's done very, very well indeed, and while I [ideally] do not want to use games like this, I have to find out about a number of players.

"We'll see what happens on Sunday but we've got loads and loads of games and it is really nice to know that I have actually two really decent goalkeepers."

That last line is the key. This wasn’t about a crisis. It was about choice. And now O'Neill has a genuine one.

Two keepers, one huge call

Pat Bonner knows exactly what it means to stand in Celtic’s goal with Glasgow watching. The former Parkhead No. 1 liked what he saw in Perth.

"Johnstone looked commanding and had that terrific reflex save. He did good, he'll be under more pressure in other games," Bonner told BBC Sportsound.

"It will be interesting to see what the manager does now - does he keep him in or go with Sinisalo? Celtic have two good goalkeepers at the moment."

That’s the crux of it. Sinisalo has done little wrong. Johnstone has just done a lot right.

A week ago, the pecking order seemed clear. After McDiarmid Park, with Ibrox on the horizon and a quarter-final on the line, O'Neill must decide whether one electric debut is enough to redraw it.