London - Jurgen Klopp said on Friday he is "absolutely not happy" with Liverpool's season so far despite his team's rich vein of recent form.

Klopp's side start the weekend sitting third in the table, having lost just once in 18 Premier League matches, and victory would carry them above Manchester United, who are not in action until Sunday, when they host Chelsea.

Liverpool are also virtually guaranteed a place in the Champions League quarter-finals after a swaggering 5-0 victory in the first leg of their last-16 tie away to Porto, which included a Sadio Mane hat-trick.

But the German boss has his sights set firmly on the challenges that lie ahead.

"I am absolutely not happy," he told reporters ahead of Saturday's match against West Ham at Anfield.

"I want to be happy at the end of the season. Happy is not the word I have in my mind, to be honest. I am sometimes fine with it, sometimes more, sometimes less."

Klopp said his thoughts turned to the match against David Moyes's West Ham immediately after the Porto victory.

"It's nothing decided this season, we are in a good position but a good position only gives you the basis for the next few games and now we have to use it as a group - players, coaches, manager and crowd," he said.

Klopp said he was proud at how forward Roberto Firmino had conducted himself following an allegation of "discriminatory conduct" during last month's Merseyside derby in the FA Cup.

The Football Association announced this week that Firmino would face no disciplinary action.

"It was a long time (between the incident and the FA statement)," said Klopp. "I'm really proud of Roberto and how he dealt with it. We were sure from the first second there was nothing to be afraid of. I am happy that's confirmed now."