Charlie Mulgrew has given his backing to Wilfried Nancy’s 3-4-2-1 system despite Celtic’s defeat to Hearts, but he believes one major adjustment is needed: shifting Kieran Tierney from left centre-back to left wing-back.
Instead, Mulgrew argued that Celtic’s tactical structure looked promising for spells, but key positional details require refining.
Nancy’s debut was always going to draw scrutiny, and much of the post-match conversation has centred on whether the formation change was too bold too soon.
Mulgrew, however, pushed back on that narrative. In his view, Celtic’s problems stemmed from long-standing issues in the final third, not from the shape itself. For him, the discussion shouldn’t be about whether Nancy’s ideas are flawed, but rather how quickly the players adapt to them.
He also made the point that system debates often overshadow something football can’t quantify, the impact of man-management.
With Martin O’Neill having previously steadied Celtic’s season using a more traditional back four, comparisons were always inevitable.
Yet Mulgrew stressed that leadership styles and player relations are hard to replicate, and tactical choices shouldn’t be judged in isolation from that wider context.
Still, Mulgrew did pinpoint one tactical tweak he believes is essential if Celtic are to maximise Nancy’s structure: Tierney must be used higher up the pitch.
The Scotland international was Celtic’s most dangerous player against Hearts, creating chances and scoring the late consolation. For Mulgrew, that alone should end any debate about his best role.
He said: (The Breakdown), “The final third has been a big problem for Celtic this year.
“For me, the formation wasn’t the issue — I don’t think a 4-3-3 would’ve made any difference. What you can’t measure is what Martin O’Neill’s man management might have brought.
“I actually thought the shape looked good early on, Celtic dominated. The one change I’d make is playing Kieran Tierney as a left wing-back.
“He was Celtic’s biggest threat — three brilliant crosses and the goal. That role suits him far more than the inverted full-back position he’s been asked to play.”
Mulgrew’s assessment stands out because it avoids the reactionary extremes that have defined much of the commentary around Nancy’s first match.
Rather than dismissing the new formation, he recognises that the early phases of the game showed promise, pressing with aggression, building effectively from the back, and creating overloads. The issue was the same one Celtic have faced for much of the season: failing to convert dominance into goals.
His argument that Tierney should be pushed into a wing-back role adds an important layer to the tactical discussion.
Tierney’s energy, delivery and ability to break lines naturally lend themselves to that position, especially within a system designed to stretch opponents and create numbers around the box.
If Nancy wants more penetration and variety on the left side, adjusting Tierney’s role may unlock a major improvement.
Mulgrew also subtly reminded supporters and pundits that systemic change doesn’t happen overnight.
Nancy arrived only days before the Hearts match, inheriting a squad conditioned to play under Martin O’Neill’s structure.
Expecting unstoppable attacking threat in game one was always unrealistic. What matters now is whether Celtic build on what worked and correct what didn’t, a process Mulgrew seems confident will take shape.
Mulgrew’s proposed adjustment for Tierney feels logical, practical and immediately impactful.
Whether Nancy implements it remains to be seen, but one thing is clear: Celtic’s evolution under their new manager will be judged not by one result, but by how quickly they learn, adapt and sharpen in the crucial weeks ahead.
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