Liverpool manager Jurgen Klopp has hailed Senegal's Sadio Mane and Guinea's Naby Keita for the impact the pair have made for the club this season.
Mane scored to help the Reds secure a 2-0 win over Villarreal in the first leg of their European Champions League semi-final on Wednesday.
The Senegal forward again played in a more central role, as he had in recent Premier League wins over Manchester United and Everton, while midfielder Keita came on as a 72nd-minute substitute.
Mane, 30, has scored 20 goals in 44 appearances for Liverpool this season, including six in his past seven outings, as the club seek to secure an unprecedented quadruple.
"He can play left, he can play central, both positions world class," Klopp said when asked why Mane has played centrally in recent weeks.
"He started for us here at Liverpool on the right wing. Some people will remember his goal at Arsenal when it was his first goal, when he cut inside and fired the ball with his left foot into the far corner. Absolutely outstanding, love it.
"There are different ways that Sadio plays and sometimes we want him to drop slightly more, but [against Villarreal] we wanted him to stay between the centre-halves and offer runs in behind. He has the skillset for it."
Mane's versatility is also something that Senegal coach Aliou Cisse took advantage as the Teranga Lions won the Africa Cup of Nations earlier this year.
Mane in Ballon d'Or contention?
Klopp said that Mane could be in line to win the Ballon d'Or if Liverpool's success can continue.
"He is world class and played again a really good game for us," the German manager added.
"Obviously this season is not even over. Historically, we have to win something to win the Ballon d'Or.
"If you're not Messi or Ronaldo, you have to win probably a Champions League, which we didn't do yet. So give us a few more weeks and then we will see where we end up.
"Sadio wants to contribute and help the team and that's what I love most of all."
Klopp also praised the impact that Keita is having this season after the 27-year-old managed to play more games this season than in his past two campaigns with Liverpool.
"He has his best season because he's fit for the longest period," the manager pointed out.
"That's good for us and for him. Naby is an outstanding player - that was always clear. In other seasons where he was not that consistent he played incredible games.
"If you go back and look at our big games, you will realize how often Naby was on the pitch in these games."
Liverpool travel face Newcastle United in the Premier League on Saturday ahead of the second leg of the Champions League semi-final in Spain next Tuesday.