Georginio Wijnaldum overcame a bout of sickness and diarrhoea to play a starring role in Liverpool's 3-0 win over Bournemouth on Saturday.
Jurgen Klopp's men returned to the top of the Premier League above Manchester City thanks to goals from Sadio Mane and Mohamed Salah either side of a sumptuous lob from Wijnaldum.
The Netherlands midfielder had a knee problem and was one of three players to withdraw on the eve of Monday's lacklustre 1-1 draw with West Ham and Klopp revealed his participation was touch and go before Bournemouth's visit to Anfield, with medical staff deciding the 28-year-old should be kept away from the team hotel.
"We had things we had to improve and then we had injuries – when fit players become ill overnight it doesn't help," he said.
"Gini Wijnaldum wasn't in the team hotel has night. He had diarrhoea and vomiting the night before. He didn't go to the team hotel because the doc thought he might be infectious.
"He came in this morning and said he was fine and what a game he played."
Klopp was pleased to see a reaction from his players – not in response to accusations they have ceded the title initiative to City over the course of back-to-back draws, but simply in terms of getting back towards the high standards they have set themselves.
"It's the nature of the thing and it's completely predictable," he said. "So long as you win, people and the media especially make you too good. If you lose [you are] too bad.
"I learnt early in my career it doesn't make sense to listen to that, but I know the boys read a lot, social media and stuff like that.
"We had an agreement; the only important thing is what we think. We were not happy with the performances in the last two games and were not happy with the set-piece defending - that is bad news before you face Bournemouth.
"We won in an impressive manner and I'm really happy about that."
Nerves were palpable during an uncertain opening at Anfield but Klopp praised the home crowd for their vocal backing.
"I have more influence on the players than the supporters, so I am more together with them. But I thought we had an outstanding atmosphere," he added.
"Supporters get a little bit nervous in certain situations. That's not a Liverpool thing, that happens at all clubs.
"Our supporters do their part of the job 100 per cent."
