Liverpool manager Rafael Benitez says he thinks Robbie Keane is part of the “long-term” plan at Anfield and has warned Tottenham that anything other than an official offer for the striker could constitute an illegal approach.

Spurs boss Harry Redknapp said this week he would like Keane in his team but when Spurs contacted Liverpool yesterday, they were told the Merseysiders were “not happy with them because of the comments from their manager about Robbie Keane."

Benitez added: “I do not think that they have come in with an offer. He has been training this week very well, he is our player and he is trying to make sure he is ready for the next match.

“I think he is a long-term part of our plans, I hope he scores a lot of goals.”

Liverpool have not officially reported the north London club to the Premier League, but Benitez has not ruled out doing so and says “it depends on their response”.

Spurs complained about Liverpool’s conduct when Keane moved to Anfield for €21million last summer. That situation was only smoothed over when Liverpool apologised and made a donation to a charity of Tottenham’s choice.

“We were very, very correct when we signed Robbie even though Spurs were complaining. Now we have this situation to deal with,” said Benitez.

The Spaniard then sowed a seed of doubt with regards to Keane’s future, when saying: “They have to make an official offer and we will say yes or no. You must do things properly, especially when you have complained about everybody when he first joined us.”

Keane was dropped by Liverpool for last weekend’s FA Cup tie against Everton, but returned to the squad at Wigan on Wednesday where he was a late substitute for Steven Gerrard.

The Republic of Ireland captain will be in the squad for Sunday’s home match against title rivals Chelsea.