Having kickstarted a week of European excellence for Scottish clubs with their win over Feyenoord, Celtic now need to show they still have the same hunger for their domestic duties.

Brendan Rodgers’ side were an immovable, invincible machine during the maiden season of the manager’s first time in charge but it has been a bumpier ride second time around. Two defeats away to Kilmarnock – the latter last weekend in the league – combined with sloppy draws at home to Motherwell and St Johnstone mean it is far from a cast-iron guarantee that Celtic will return to the Champions League next year.

Being knocked out of Europe at least means they now have no choice but to focus all their energies on trying to retain their title and, with Rangers not in league action this weekend, an opportunity has presented itself for Celtic to stretch their lead to eight points, albeit they will have played two games more than their rivals. To do so, however, they will need to reprise the fighting spirit evident against Feyenoord and not the calamity of Kilmarnock.

Has Joe Hart waved goodbye to the Champions League? The Celtic keeper does not know what the future may hold.

“We’ve got to use the bounce we get from this [Champions League win],” said goalkeeper Joe Hart. “The manager alluded to it post-Kilmarnock but we came away from what makes us a good team a little bit in the second half in the conditions. We made it into a physical game and came off second best, simple as that. Against Feyenoord we stuck to what makes us good and what makes us tick. Fair play to Kilmarnock for being good at what they do but we have to stick to what we’re good at as when we do we can get results. We have to make sure we’re ready with our best 18 players and really look to put it on Hearts.”

The bullet points on Hart’s CV will highlight his 75 England caps, his two Premier League titles with Manchester City and now numerous baubles as a Celtic player. The 36-year-old, though, was honest enough to admit that sometimes opportunity arises when least expected as he praised Liam Scales, Stephen Welsh and Gustaf Lagerbielke, the unlikely match winner against Feyenoord, for making the most of their moment in the spotlight.

“Football’s mad, isn’t it?” he surmised. “Look at Liam, look at Lagerbielke. It’s about moments, you have to take your moments. I’ve lived this career for a long time now and not everywhere I’ve got has been down to me always being a stand-out. I’ve also been at that messy level and it’s just about being in the right place at the right time, and having the right attitude and commitment.

“Liam was excellent last year on loan at Aberdeen and it was no secret that he was looking to do that again. They really wanted him but his moment came here and he’s stepped up and done really well. He’s hung in there. You’ve got to. There are so many good players out there so once you’ve got a foothold you can’t let anyone take that from you.”

If that was Hart’s final ever Champions League appearance then he will have bowed out having made a number of key saves to pave the way for victory. “It might be, it might not be. Who knows what the future holds? I can only play in the games I’ve been given right now. And I was pleased to play a part in a big win. But the nature of the beast is we have to be ready to rumble on Saturday.”

'Football's mad': Candid Celtic keeper Joe Hart mulls over rollercoaster week and what his own future might hold