Martin O’Neill has explained his decision to leave James Forrest out of Celtic’s starting lineup for today’s League Cup semi-final against Rangers, despite the winger’s impressive performance in the 4–0 win over Falkirk midweek.

Forrest, who rolled back the years with his energetic display at Celtic Park on Wednesday, finds himself among the substitutes at Hampden this afternoon.

But O’Neill insists the decision was purely down to managing the veteran’s fitness and keeping him ready to make an impact if needed.

“Well, first of all, I thought that James Forrest was excellent for us, really, really good,” O’Neill said on Premier Sports.

“And with James, you just have to treat him accordingly in the sense, you know, he’s passed 30 by a couple of years.

“So, who knows how long this game might last, but if it did go for a fairly lengthy period of time, I can imagine James coming on and playing his part.”

O’Neill’s comments hint at a potential super-sub role for Forrest, whose experience and composure could prove crucial if the tie goes deep into extra time, as it did the last time Celtic met Rangers at Hampden, when the Hoops triumphed on penalties to lift the League Cup.

That was a game that Celtic probably got lucky in, and fans will be hoping that this match doesn’t unfold the same way.

Forrest, a serial winner at Celtic, was in the Celtic academy when O’Neill was manager at Celtic first time around.

Now, two decades later, the winger could again have a decisive role to play in a derby that could define Celtic’s season.

Hampden is packed, and kick-off is imminent.