Jurgen Klopp has revealed Georginio Wijnaldum was so ill with "diarrhoea and vomiting" in the days leading up to Liverpool's 3-0 victory over Bournemouth, that he was not even with the team at their hotel on Friday night.
Wijnaldum scored a brilliant goal against the Cherries, lobbing a beautiful effort over Bournemouth goalkeeper Artur Boruc to give his side a 2-0 advantage in the contest.
Sadio Mane opened the scoring, while Mohamed Salah also found the back of the net as the Reds returned to the top of the Premier League , three points clear of title rivals Manchester City, to snap out of a week of indifferent results.
Back-to-back 1-1 draws against Leicester and West Ham had allowed Pep Guardiola’s side to return to the summit for the first time since mid-December with their 2-0 win against Everton at Goodison Park in midweek.
Klopp was subsequently forced to deny claims in the build-up to the Bournemouth game that Liverpool were starting to feel the pressure in the title race.
There were a few nerves in the opening stages at Anfield, but as soon as Mane met James Milner’s cross to head home the opener after 24 minutes the result was never really in doubt.
Klopp was delighted at the resilience of his side, particularly as a number of his players had been suffering from illness midweek, including Wijnaldum, whose ailment was so severe he was kept away from the team right up until today's match.
“We were not happy with the performances from the previous two games and struggled a bit with set-pieces. There were a lot of things we had to improve,” he told BBC Sport.
"We have had injuries and fit players who have become ill overnight on the day before a game.
"[Wijnaldum] didn't sleep in the team hotel last night. He had diarrhoea and vomiting two nights earlier so he couldn't come to the team hotel.
"We have high expectations and today we won in an impressive manner - we had some outstanding performances on the pitch. Goal number three was world-class.
"We wanted to show a reaction. It's our job not only to come through but to really perform and convince."
Klopp acknowledges that there was a bit of tension in the air early on at Anfield but was keen to play down its significance.
"Supporters get a little bit nervous for all sorts of reasons. That's not a Liverpool thing - it's a football thing,” added the German.
Manchester City can return to the top of the table on goal difference with a win against Maurizio Sarri’s Chelsea at Etihad Stadium on Sunday, though the Reds will once again have a game in hand following the contest.