Messi was instrumental during Barca's 5-1 Nou Camp win against Lyon on Wednesday, scoring twice and creating the others for the Spanish champions, while Ronaldo's hat-trick against Atletico Madrid in Turin 24 hours earlier was just the latest chapter in the Juventus forward's incredible Champions League story.
Since the world's most expensive defender arrived at Anfield in January 2018 he has played a significant part in making the Reds' defence the toughest in the Premier League.
"I could write a book about his skills, strength, how much I like him and what a fantastic person he is; so young, so mature, so strong", said Klopp. "They were the better team over the two legs, we deserved to lose".
'It's a hard place to come. The same applies to Messi, who has not been eliminated from the competition by an English team since Chelsea beat Barcelona in the semifinals en route to their win in 2012.
GETTY IMAGESVirgil van Dijk outjleaps the Bayern defence to head in Liverpool's second goal from James Milner's cross
Another key factor in Liverpool's continued ability to stay in the race at home and overseas is the form of Sadio Mane. The Senegal global also headed in Liverpool's third of the night for his 10th goal in as many games in all competitions for the Merseyside club.
'It's so obvious that I don't have to speak about it, ' said Klopp of Mane's recent form. "The first goal was ridiculous really, how he finished it off, the calmness and the finish", Milner told reporters.
'He knows it, everybody knows it. We found that and that makes me feel really proud and happy.
"You have to stay in a game, be really stable and have answers to all the questions, change things, use different tools". You saw a set-piece can be decisive in a match like this.
Serge Gnabry had forced an own goal from Joel Matip to equalise in the 39th minute, but Liverpool went ahead again through a corner when Virgil Van Dijk met James Milner's cross with a thumping header with 20 minutes to go.