Hearts manager Robbie Neilson has confirmed why goalkeeper Craig Gordon is not in the matchday squad to face old side Celtic.

The 39-year-old - who won five league titles, two Scottish Cups and five League Cups at Parkhead - has played every minute of the Jambos' opening four games of the season but is not in the matchday squad for Sunday's trip to face the champions.

Neilson, whose side lost 2-1 in the first leg of their Europa League qualifier against FC Zurich on Thursday, spoke to BBC Sportsound ahead of the match about the raft of changes he has made to his starting XI.

He said: "We had a couple of knocks after the [Zurich] game - Craig Gordon, Stephen Kingsley, [Craig] Halkett, Barrie [McKay] and a couple of other guys so we felt today we just couldn't take a risk with any of them."

Expanding on Gordon's situation specifically, he said: "Craig Gordon is Scotland's number one so it can be difficult to oust him but he's got a back spasm so we decided to take him out in preparation for Thursday. It's a great opportunity for Ross [Stewart] to show what he can do."

Celtic line-up: Hart; Juranovic, Carter-Vickers, Jenz, Taylor; McGregor, Turnbull, O'Riley; Jota, Maeda, Kyogo Substitutes: Siegrist, Starfelt, Giakoumakis, Abada, Mooy, Bernabei, Hatate, Forrest, Ralston.

Hearts line-up: Stewart; Sibbick, Rowles, Cochrane; Atkinson, Halliday, Haring, Mackay-Steven; Forrest, Ginnelly, Boyce. Substitutes: McFarlane, M Smith, Grant, Shankland, Devlin, McKay, Neilson, C Smith, Pollock.