They say hindsight is a wonderful thing. For Bayer Leverkusen sporting director Simon Rolfes, however, it has provided nothing but a tinge of regret from a chaotic evening in Glasgow.

The German chief, admittedly, left Scotland delighted with his club's performance and result in their last 16 first-leg clash against Steven Gerrard's game Rangers side. But upon reflection, knowing what he knows now, Rolfes can't help but think the victory may have come at a cost.

March 12, 2020, in front of a packed 50,000 plus supporters within Ibrox, Leverkusen cruised to a 3-1 win. Less than 24 hours later, the whole of Scottish football was suspended indefinitely. Social distancing was enforced, lockdown was on the horizon.

Allowing a near capacity crowd inside the stadium during the previous evening's clash now looks insane to Rolfes. Undoubtedly, the 90 minutes will have allowed the spreading coronavirus to grow ten-fold. Large gatherings have since been cancelled. Tiny gatherings, even, are frowned upon.

Rolfes just wishes those in charge had thought more about the practicalities and, indeed, consequences, at the time. "When you look back, for me, it was strange," the former midfielder admits. "At that moment we had to beware and know that things were changing, but nobody could realise what sort of impact it would have at that time. Looking back it was quite dangerous."

Bayer Leverkusen and the rest of the Bundesliga have since taken steps to avoid any further damage done by Covid-19, but they are far from out of the woods yet. Like many other clubs around the world, their players and management staff in Peter Bosz have accepted wage cuts and deferrals to ensure their club survives the uncertainty.

And listening to advice from the health board in Germany, and politicians, is vital. "A key for a possible restart of the competition is the solidarity in the Bundesliga," he added. "Everyone is working together within the league and within the clubs, helping each other and the players are showing real responsibilty by accepting reduced salaries.

"The excellent healthcare system in Germany helps by guaranteeing the necessary framework we need, and I think that's all important in such a crisis. To make sure we are able to come back. I think our league can also be a role model to some other countries to really get together and unify, so they can play again.

"That's a big strength we have here, that the league is doing a very good job. Clubs are together, we have a broad and detailed medical concept from the league to work with, an outstanding healthcare system and we're working together with politics so we can hopefully play again in the near future."

If they can get their domestic football back up and running, Rolfes hopes Uefa can also kick-start the Europa League again soon. Not that he's advocating for the governing body to rush things. A second-leg match awaits against Rangers and the sporting director knows the Glasgow giants will provide another tough game, as they did at Ibrox.

"Rangers were competitive and there was a lot of power from the stadium in a fantastic atmosphere," Rolfes said. "They are a good team and were a big challenge for us, but we managed to resist and came to a great mental performance from our team. We have a good chance to make it through to the next stage, we want to do it.

"The players loved to play there and it was the last game in Europe with spectators. The players remember the game and the feeling and the fans singing their songs, and they loved it.

"The big strength of Rangers is their quality as a team, that was what we were aware of. Their team spirit and supporters, their mentality and football culture. We knew about that and were prepared. We had the confidence, though, that we wanted to win in Glasgow.

"We have the confidence to get to the next stage because we have a really good squad this season. That's our goal, we want to win the second game at home."

Leverkusen will certainly not be taking their lead for granted. They have ambitions, of course, to win the tournament. But Rolfes knows his club will have to see off Steven Gerrard's charges before even contemplating any further success. "It's always important, for me, to win the next game which is against Rangers," he said. "We obviously have high ambitions in the Europa League but also in the cup and Bundesliga. But we only focus on the next stage, and that is Rangers. We are an attacking squad."

Despite Rangers having the power from their supporters in the first-leg, it is looking increasingly likely that, should the second-leg be played, it will be contested behind closed doors. Exactly what, Rolfes believes, must happen. Though he does not see that as any sort of disadvantage to his club's players - because they are professional enough to get the job done in any circumstance.

He added: "I don't think [playing without fans at home] will be a disadvantage because it will be the same for both teams. It's all a question of the quality, of the squads and players. And we have a lot of confidence in our players.

"We have a really good squad with some fantastic players who have the mentality to win games. It's fantastic to play in front of fans and the atmosphere, we will miss it, but we want to play and want to win anyway. Without spectators, we are still attacking."