Scott Sinclair has challenged Celtic to back up their treble-winning campaign by going out and claiming all three domestic trophies again next season.

Celtic’s top league scorer sees no reason why his side can’t go through the Scottish football season unbeaten again, and he also holds ambitions of progressing further than the group stages in the Champions League.

With the team now settled and with one or two additions perhaps still to come, Sinclair thinks that Celtic will be an even more formidable outfit when the action kicks off again in July.

Read more: Stuart Armstrong can be a future Celtic skipper says John KennedyGlasgow Times: Treble yell: Scott Sinclair has called upon his Celtic teammates to go for the clean sweep again next season.

And when asked how his side can possibly top their “Invincibles” campaign, he said: “You do it again next season.

“Not just that, we have to look at the Champions League as well. We want to get into the group stage again and then hopefully progress even further than we did this season.

“There were a few additions to the team at the start of the season. Everyone knows each other now and throughout the season we have got better and better.

“Now we can go on holiday and relax, although some of the lads will be on international duty, then come back stronger for next season.

“If you look at every single player in our squad, we are winners. We want to win, even in training. The amount of tackles that fly in in training - it’s just what we do.

“We haven’t just won this treble by luck. It has come down to determination, hard work and it has paid off.

“We are all trying to take it in while everyone is still high on the emotions of it. Once everyone goes away on holiday and then comes back for pre-season training, or maybe even six months from now, we can reflect properly on it.

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“It might be a case of suddenly thinking ‘Wow, we went a full domestic season unbeaten in winning the treble’. It’s never been done before.”

It is his manager’s relentless insistence on the highest of standards being applied at Celtic that gives Sinclair such confidence that this side can improve even further next season.

And he provided an insight into what happens when those standards do slip, as they did momentarily in training during the run-up to last week’s Scottish Cup final.

“He sent us in early,” said Sinclair. “He told us we’d had 208 training sessions during the season and had one bad one, which was two days before the cup final.

“I’m not too sure why it was a bad session, I can’t put my finger on it. It was just a little bit slack. It goes to show the high expectations of the manager. He doesn’t like anyone slacking.

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“He always wants 100 per cent, he never lets anyone relax during a session. That’s why we keep winning.

“For ourselves, we didn’t want to get so far and then it didn’t happen on the last day in the Scottish Cup Final.

“But it did happen and it just goes to show the winning mentality, character and mental strength of the squad.

“When we went a goal behind [in the final], we needed to pick ourselves up quickly and we did that with the equaliser. It’s great to be part of history now.

“A lot of the lads played a lot of games during the season, we’ve enjoyed winning, but maybe some of us do need a couple of weeks off now. We will hopefully come back and be refreshed.

“Personally, I feel as if I could keep going. I’ve had a few years out, so I feel fresh. I haven’t really racked up many miles on the clock. I feel younger than I am.”