Martin O'Neill has had to rely on a number of talented youngsters to get Celtic through a rough patch, but ruthless decisions are incoming. The Bhoys seemed to hit rock bottom when they lost three straight games ahead of the last international break, leaving O'Neill questioning whether he would continue in the role.

That was despite the Hoops sitting top of the table at the time, and two league wins since, including a 7-1 win over Hearts on Sunday have only strengthened their position at the top of the Premiership. European form has been a different story, and Celtic are winless in the Europa League ahead of Thursday night's home clash with Celta Vigo, which will be a pivotal clash in their bid to progress to the next round.

In that game, Celtic are once again likely to rely on some of their talented younger players, with Callum Osmand almost certain to keep his place as long as he is deemed fit enough to play. Osmand, who is a striker, played out wide and scored twice against Hearts on Sunday, providing a brilliant first-half display before being brought off due to recently returning from a lengthy injury layoff.

At centre-back, Dane Murray, who is now 23 years of age, put in another solid display as he continues to deputise for Cameron Carter-Vickers, who has been dealing with a muscular strain. Carter-Vickers is back in training, but he is unlikely to start, and Auston Trusty is unavailable on Tuesday night due to the death of his father.

“I thought he was really really good, played very, very strongly. That’s not really his position at the end of it all, although he adapted brilliantly." O'Neill on Osmand

At right-back, Colby Donovan has been excellent in the absence of the reliable Alistair Johnston, who has been out since August after picking up a hamstring injury on the back of a busy World Cup summer and an early start to the season.

Tough decisions are coming for O'Neill

O'Neill will be delighted to see younger players stepping up to the plate, but there are some tough decisions to come. Osmand was brilliant over the weekend and will have a small window to make his case ahead of Jota, who is currently building up his fitness with cameos after over a year out. Yang Hyun-jun is also close to returning from a hamstring injury, and he was in fine form ahead of heading off to the Asian Games in early September.

Osmand is good, but he is going to have to be consistently good to avoid dropping behind those two players when they are fully available.

Elsewhere, Trusty will be back within a week or two following his sad personal situation that he will be given time off to deal with, and with Carter-Vickers back in training, it's likely O'Neill will turn back to the partnership of Trusty and Carter-Vickers, while Liam Scales is also a preferred option.

Last but not least, Johnston is back in training ahead of Thursday night, and while Donovan has been one of Celtic's best players this season, already a strong contender for Young Player of the Season, Johnston is simply a better player at this stage, as one of the Bhoys' best and most reliable players as a whole.

All three youngsters will still play a part going forward, no doubt, but the reality is that O'Neill is going to have more senior options he will have to rely on sooner or later, and that's going to mean some difficult decisions.