Brendan Rodgers has told Liverpool’s owners, Fenway Sports Group, the club needs to buy “some men” this summer to eradicate the lapses that have plagued his debut season at Anfield.

Missed opportunities and defensive errors again cost Liverpool on Thursday when losing 2-0 at Zenit St Petersburg in the Europa League, leading Rodgers to question the mentality of the squad and strengthen his calls for greater character. Ashley Williams, the Swansea City defender who will oppose Liverpool at Anfield tomorrow, is one such target for Rodgers, though he may have to convince FSG to sanction a move for a 28-year-old.

Liverpool have failed to challenge for a top-four place this season and a Europa League exit to Zenit would end their prospects of a trophy. The manager believes it is the calibre of signing, not the quantity, that will instigate an improvement.

Rodgers said: “The biggest thing we need this summer is to bring in some men, some character that allows and supports the other men to see the games out. That is the biggest thing for me. Look at Jamie Carragher. He is our best defender, he is 35, but we are losing that character. That has to be replaced somehow.

“I also think there are other areas of the team that need improving. They have to be established players and they have to have that hunger, that is the key thing.”

Liverpool’s managing director, Ian Ayre, has denied that FSG has implemented a rigid policy of signing only young players under Rodgers, although the club have not bought anyone over 24 since he became manager.

Liverpool paid just under €10 million for 20-year-old Philippe Coutinho last month, after Rodgers said there was a need for experienced leaders, and doubts remain over the extent of the manager’s influence on transfer policy.

Rodgers insisted that Liverpool will not require “wholesale changes” this summer. “I don’t think massive surgery is needed,” the manager added.

“Maybe if we had a few more of Daniel Sturridge’s capacity in the group that could set us up. Technically we have shown we are very capable, tactically we have not been found wanting like in the recent two games against Arsenal and Man City. The condition and intensity of their work is high so that only leaves one thing – mentality. That is the area which needs to improve and to do that we need character.”