LIVERPOOL, England -- Jurgen Klopp's team will go down in Liverpool history as the side that ended the club's 30-year wait for the league title. Not even the threat of a Premier League shutdown because of the coronavirus will deny Liverpool the chance to lift the trophy, though they might have to do so in an empty stadium if English football is the latest domino to fall among Europe's top leagues.

But the best teams are only as strong as their weakest links, and Liverpool have now been knocked out of two competitions in the space of eight days because their backup goalkeeper is nowhere near as good as their first choice.

With Liverpool eliminated from the FA Cup by Chelsea last week and dumped out of the Champions League on Wednesday, thanks to Atletico Madrid, both defeats came as a direct result of mistakes made by Adrian, the Spanish keeper who is deputising for the injured Alisson Becker.

At the start of the season, Adrian was the penalty shootout hero of the UEFA Super Cup triumph against Chelsea in Istanbul, but as the campaign draws to a close, his fumbles and errors of judgement have played a key role in Liverpool facing up to the prospect of a glorious year fizzling into a tale of what might have been.

Although winning the Premier League title will unquestionably make this a successful season at Anfield, it promised to be so much more when they travelled to Madrid for the first leg of this Champions League tie three weeks ago. Back then, Klopp's men were still unbeaten in the Premier League and still within a shout of adding the FA Cup and Champions League to the Super Cup and FIFA Club World Cup they won earlier in the season.

"We know in the last two years we had some lucky moments in the Champions League," Klopp said. "You have to, to reach two finals, but today it was everything was against us in the decisive moments. We accept it, of course, but it doesn't feel right tonight.

"I realise I am a really bad loser, especially when the boys put such an effort in against world-class players on the other side who defend with two rows of four.

"Our main mistake was to not score the second goal five minutes earlier. We scored it in extra time and not in the 90 minutes."

Saul Niguez's goal in Atletico's 1-0 first-leg win at the Estadio Metroplitano has triggered a slump that has seen Liverpool suffer four defeats in six games in all competitions. They are out of the FA Cup, they are no longer unbeaten in the Premier League, and they have seen their hopes of retaining the European Cup ended by Diego Simeone's Atletico.

If Manchester City lose at home to Burnley this weekend, Liverpool can clinch the title on Monday with a win against neighbours Everton at Goodison Park, but once the title is won, there will be an inevitable sense of anti-climax and missed opportunity in the other competitions.

Liverpool should still be alive and kicking in the Champions League, despite Atletico's three-goal show in extra-time, which saw them end the home team's 68-game unbeaten run at Anfield in the Premier League and Champions League. Liverpool created 34 goal-scoring chances, including an Andy Robertson header against the crossbar, and dominated possession with 71%, but their Achilles' heel was the man in goal.

Meanwhile, in the other goal, Jan Oblak made save after save to keep Atletico in the tie to underline his status as one of the best in the world. Perhaps it is harsh to focus on Adrian because the former West Ham keeper certainly did not intentionally make the mistakes that cost his team. But as Liverpool discovered when Loris Karius committed two howlers during the Champions League final defeat against Real Madrid in 2018, if your goalkeeper is not at the same level as the rest of your players, it will cost any team.

A poor Adrian clearance, while Liverpool were 2-0 ahead on the night following goals from Georginio Wijnaldum and Roberto Firmino, led to Marcos Llorente giving Atletico a lifeline on 96 minutes. Adrian also slipped when he attempted to keep out the striker's shot. That goal gave Atleti belief, and they smelled blood. Nine minutes later, Llorente scored again to put the Spaniards ahead overall before Alvaro Morata sealed a 3-2 win with a strike in the 120th minute.

But the crucial moment was Adrian's mistake for the first goal, just as it was against Chelsea in the FA Cup, when he fumbled Willian's early strike into the net. That is the problem with understudy goalkeepers. They are rarely in the same league as the No. 1, so they are exposed when the heat is on, and mistakes are made.

Still, Adrian will get a Premier League winners' medal when they are handed out in May, and he will have earned it for his performances earlier this season when Alisson was sidelined for two months by a calf injury. But had he been more capable, or had Alisson been fit, Liverpool might still be chasing three trophies this season. As it stands, they have just one left to win. They will win that, but one major trophy doesn't feel like quite enough for the remarkable season Liverpool have had.