Manchester City midfielder Ilkay Gundogan said on Tuesday suffering from Covid-19 has changed his attitude to the outbreak as he prepares to feature for Germany.
The 30-year-old missed Premier League games in September after suffering with Covid-19, which he admits changed his thinking.
"I didn't take the coronavirus seriously before my illness - afterwards my attitude changed," Gundogan said ahead of Wednesday's friendly against the Czech Republic in Leipzig.
"It doesn't just hit you physically, but psychologically as well."
It was an "extremely unpleasant time" for the defensive midfielder, who felt "totally worn out" and his sense of taste "was completely gone".
Gundogan has recovered and feels back in his "rhythm" after scoring two goals in his last three Champions League games.
However, a phonecall from his anxious grandfather in Turkey shook him when he was ill.
"For me, it was worst when my grandfather called and cried for most of the phone call," Gundogan revealed.
"That showed me that he was very worried about me, but also for himself. I will never forget that conversation, because it touched me so deeply," he added.
Gundogan said he is now determined to do whatever he can to stop the virus spreading.
"We have a responsibility, we must not be selfish and we must protect ourselves as best we can," he added.
- Loew's captain -
With Bayern Munich's Joshua Kimmich sidelined until January with a knee injury, Germany coach Joachim Loew said Gundogan is a "key player" for their Nations League matches against Ukraine on Saturday and Spain next Tuesday.
However, after the midfielder played 90 minutes for City in Sunday's 1-1 draw with Liverpool, Loew is in no rush to play Gundogan on Wednesday.
"Ilkay had a very intensive match - we will discuss whether he maybe plays 45 minutes or some of the second half," Loew said on Tuesday.
However, as Germany captain Manuel Neuer will be rested, Gundogan could be handed the captain's armband at some stage in Leipzig.
Having previously led his country in March 2019, Gundogan welcomed doing so again.
In 2018, he had his loyalty to Germany questioned over a controversial photo of him alongside Turkey president Recep Tayyip Erdogan.
Now Gelsenkirchen-born Gundogan wants to nail down a place for Germany with one eye on next June's Euro 2020 finals.
"I want to be a regular - that's my ambition," he added.