In Callum McGregor you have arguably the finest midfielder in Scotland.
A player who would walk into any team in the country, and wouldn't look out of place in the vast majority of sides around Europe.
So what is the one thing you don't want to do when you have a player of that quality? Play him out of position.
McGregor lined up at left back for Celtic against CFR Cluj in their Champions League qualifying defeat on Tuesday night and it was a move that baffled supporters.
Neil Lennon explained that he did so to fit in Olivier Ntcham as he looked to get more 'technicians' in the team.
The problem with that, as good as Ntcham can be, is that McGregor is Celtic's best technician by a country mile.
When you have a player as good as McGregor, you move players around to fit him in his best position, not move him out to play others.
But it's not the first time McGregor has played at left back. There are times you have to fill in when needed and for short times in games that can be acceptable.
Since making his first full back appearance in November 2016 against Kilmarnock, McGregor has played a total of 12 times on the left hand side of defence.
On four of those occasions it has been to fill in. They came in short spells with seven minutes during the Scottish Cup Final against Hearts, 21 against Rangers in March, 30 minutes in a win over Albion Rovers and 22 in a 4-3 victory against Motherwell.
Of the other eight he played at least 68 minutes in an unnatural position and that is the games that matter.
In the early days, you could almost understand it. McGregor wasn't at the level he is now and there was a lot of competition in the middle of the park.
In the eight games where he has spent the majority of the game at left back, Celtic have won four of them.
Three of those victories came in the first four when he played against Kilmarnock in 2016 as well as Aberdeen and Hamilton in 2017.
Since then, there's only been one game in five where Celtic have been victorious.
That came in a 3-1 win over Hearts on the final day of the 2017/18 season with McGregor in defence.
There's also been draws against Motherwell and defeats against Rangers and Cluj.
Brendan Rodgers was heavily criticised when he deployed McGregor in the unfamiliar role in December as Rangers dominated their rivals and won their first league derby in seven years.
During that game, McGregor attempted just 54 passes while on average over last season he would attempt 66.
It took away his natural game with Rodgers' midfield trio of Ntcham, Scott Brown and Ryan Christie being overpowered by a combative Rangers team.
The Hoops struggled to get their foot on the ball in that one and there was a calmness missing against Cluj as well.
Now, there's no way McGregor can be blamed for the defeat to Cluj. He wasn't at fault for any of the goals and tried his best.
The issue is you miss out on so much that he offers when he plays there instead of in midfield.
At the beginning of his Celtic career, the Hoops could afford to move McGregor to left back.
Now? The results and performances suggest he is a must in the middle of the park.
A 50 per cent win rate doesn't make for kind reading.
Celtic results with McGregor at left back
Celtic 3 Cluj 4 (90 minutes)
Rangers 1 Celtic 0 (90 minutes)
Hearts 1 Celtic 3 (90 minutes)
Celtic 0 Dundee 0 (68 minutes)
Celtic 3 Ross County 0 (90 minutes)
Motherwell 0 Celtic 0 (90 minutes)
Celtic 3 Hamilton 1 (90 minutes)
Celtic 2 Aberdeen 1 (74 minutes)
Kilmarnock 0 Celtic 1 (90 minutes)
