The Brazilian started the game on the bench after he suffered a nasty eye injury during the 2-1 Premier League win over Tottenham Hotspur at Wembley last weekend.
However, the attacker was fit enough to come on and he ended up netting the all important stoppage-time winner at Anfield after PSG had levelled the score in the Champions League tie at 2-2.
And Klopp has admitted his delight at having Firmino available for selection again after his heroic performance from the bench on Tuesday night at Anfield.
Speaking at his post-match news conference, Klopp said: “We had the opportunity to bring on Bobby Firmino.
“There was no chance yesterday [Monday], absolutely no chance today before [training] and then this morning he came in said, ‘I am fine, I can open the eye again!’ so it’s good, it helps! It was good.”
Liverpool FC will now switch their focus back towards Premier League affairs as they look to try and continue their 100 per cent start to the new campaign.
The Reds will host Southampton at Anfield on Saturday as they bid to keep up a Premier League title bid following their trophyless campaign last term.
Liverpool FC are currently joint top of the Premier League table along with early leaders Chelsea FC.
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