The theory and the reality are different for Dujon Sterling right now. Before he can prove that he can replace James Tavernier, he must prove that he can replicate the Rangers captain.

Whatever criticisms can be directed at Tavernier over the course of this term or over his Ibrox career, his physical conditioning and robustness cannot be questioned. The ability to play week in and week out, to always be available, to always put yourself forward, simply cannot be overlooked. Indeed, if Rangers had more players like that in recent seasons their chances of silverware successes would not have been undermined and undone by injury issues.

The moment that Sterling took over from Tavernier on Sunday at Hampden could have been seen as a changing of the guard. As Philippe Clement’s side went in search of a League Cup final spot, the man who has stood up to be counted more often than any other over the last decade was the one that was removed from the action. History shows that it was the right call.

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Supporters would now like to see Clement make that same decision from the start of matches and give Sterling a run at right-back. That is easier said than done, though, especially when Sterling must convince that he can get through the work in the same way as his skipper.

“I'm not sure that he's ready now for 90 minutes in games,” Clement said as he spoke ahead of the Europa League fixture with Olympiacos. “So that he needs to prove the next weeks. He's been struggling two months with not a big injury, but something that stopped him from really sprinting. He’s not been his normal self, like it was last season. Because of that he didn't have the [fitness] level that he had before. That's why he played less minutes.

“Working with the medical staff we found a solution how to solve it. It's solved now. He feels better and that's why he played better also. It's normal that he will get more minutes if he plays better. Those are the rules in football, in the squad. It's about proving yourself in the training and in the games when you come in that you're ready.

“I hope we can get back the Dujon that we saw last season. Because in the beginning of the season he almost didn't play. I was surprised when I came in the first weeks that he didn't play.”

It is likely that Sterling will have a role to play at some stage in Athens. That is not the case for a handful of walking wounded, however, and Ridvan Yilmaz and Rabbi Matondo are still not available after returning to training with the squad.

Clement needs as many players as he can get to handle a schedule that sees Rangers compete across competitions every few days. The situation is not at crisis point this season at least.

“No, we need to be realistic about that,” Clement said of the injury state of play. “I don't think there's one squad in the world where there are no injuries. That’s a utopia. In periods yes but last season we had in a lot of moments 12 players out. That's never been the case this season. So there are changes made in staff, in the way of working, in a lot of things. And we start to see also the benefits of that.

“For example, John Souttar in his career never played so many minutes as he's been doing now. Never. Before he always had injuries in those moments and there are other examples also in that way. So there are good steps made. We still have to make steps to make the team in general more robust. I'm happy to see some players back.”

Clement does not have Ianis Hagi or Danilo at his disposal in continental competition and his forward options have been depleted further. Tom Lawrence was forced off during the first half on Sunday and has been ruled out for up to six weeks.

The playmaker has five goals in 15 appearances this season. Lawrence may not be a firm favourite with the fans, but he has the faith of his manager. His absence will be felt by Rangers.

“Yeah, of course he's been important,” Clement said. “He took the role really well. This season he scored several really important goals, but not only that, also in the play, also defensive-wise. But it gives chances to other players to prove themselves. It's like that in football. It's part of football also.

“We don't have many [injuries] for the moment, touch wood. We want to continue in that way - with all the squad to be available. He started the season really well. He has played a key role in the team and has helped both in the play and the goals he's scored.

“And in general, the fact that he creates chances for the other players. But that's football. We play with the team we have and we will keep the players available.”

The journey to Athens on Wednesday gave Clement a chance to finalise his preparations for the fourth fixture in this new league format. He referenced the anticipated atmosphere at the Georgios Karaiskakis Stadium and backed his players to handle whatever the home fans bring to the occasion.

(Image: Rob Casey - SNS Group) The fact that Olympiacos were Conference League winners last term shows their pedigree on the European stage. If Rangers are to overcome them, the bar will need to be raised once again. If it is, adding three points to those collected against Malmo and FCSB would leave Clement’s side in an encouraging position in the standings.

“Clearly more,” Clement said when asked how big a performance his side will require to claim a third victory of the campaign. “Because they won also against Malmö. And they won against Braga and I rate Braga also highly and they won with 3-0. No, we need a really big performance from all the squad, all those starting and coming in but I feel also that they are very hungry to do that and going to this final gave also another part to the group. It's now to confirm that in this game at a higher level against a better opponent, to raise our level again.”