Bayer Leverkusen coach Xabi Alonso and his players have spent all season trying to play down their remarkable achievements. (More Football News)

No longer. "Three games left for immortality,” is how goalkeeper Lukas Hradecky sums up the situation ahead of a run of games which could cement his team's season as one of the greatest ever in European soccer.

Leverkusen has been confirmed as German champion for more than a month. On Saturday, against Augsburg, it can become the first team ever to complete a full Bundesliga campaign unbeaten.

As if that wasn't enough, Alonso's team then plays Atalanta in the Europa League final in Dublin on Wednesday and Kaiserslautern in the German Cup final in Berlin three days after that on the hunt for an historic treble.

When the season began in August, no one expected Leverkusen could do this well, not even Alonso.

“The target was obviously to qualify for the Champions League but beyond that target, my goal was to play well," Alonso says.

“After two or three Bundesliga games, I had the feeling that we could have a good season and now what we have done is super. We have the chance to do a little bit more to have an historic season.”

Just two months ago, Alonso refused to even discuss the Bundesliga title race, even as title challenger Bayern Munich crumbled and Leverkusen's lead grew.

It's been a similar story with the looming prospect of an unbeaten season. “We only really started talking about it two or three weeks ago,” defender Josip Stani?ic says.

“Before that, it somehow wasn't an issue. There were far too may games left, anyway, and you know anything can happen at any time. Now, we've got three games to go and it would be sad if we were to lose one of those three.”

Even as Leverkusen's players ready for these last three crucial games, there are questions around how many key players the club can keep.

Stani?ic is the likeliest to be leaving because the Croatia defender is only at Leverkusen on loan from Bayern Munich. Even though he had a decisive impact on the title race by scoring against Bayern in February, there's no sign as yet of Leverkusen making any move to keep Stani?ic permanently.

Alonso's decision to stay with Leverkusen in March after being linked with Bayern and Liverpool was a signal that he wants to keep his squad together and see how much more they could achieve in the Champions League.

Still, German newspaper Sport Bild reported this week that right back Jeremie Frimpong could seek to leave. Frimpong, who has 14 goals in all competitions this season, is contracted through 2028.

“I'm not thinking about staying, going, things like this,” Frimpong said last month when asked about his plans.

Alonso didn't comment directly on Frimpong's future but underlined the speedy Dutch wing back's importance to the team, adding that the way Leverkusen plays gets the best out of him.

“Since the first day, Jerry has been a key player for us and for myself,” Alonso said.

“He's a great guy, his personality, he brings a lot of joy to the locker room, so you need to keep him having this joy, but as well, becoming more mature. That's why he has developed this year not just as a football player, as a professional as well.

"And on the pitch he's so special. You can't find many Jeremie Frimpongs. And for us, he's very, very specialist in our system, and I think it's almost a tailor-made system for Jerry."