The Reds boss saw his side's chances of a top-four finish all but come to an end when they lost at home to West Brom on Monday, before suffering a devastating Europa League defeat to Zenit, leaving them with only the slimmest chance of claiming silverware at the end of the season.
Rodgers believes the Merseyside club must replace their transfer policy of signing young promising talent with sell-on value with one that allows him to add experience to his squad.
"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," Rodgers told The Mirror.
"That is the reality of it - we haven’t been good enough. In order for us to be up there consistently we need to improve in terms of our mentality.
"Technically we are very capable, tactically we have not been found wanting, the condition and intensity of their work is high so that only leaves you one thing - mentality. That is the area which needs to improve and to do that we need character."The Liverpool boss highlighted Jamie Carragher, who is set to retire at the end of the season, as an example of the type of character his side needs.
"Look at Jamie Carragher, he is our best defender, he is 35 but we are losing that character," he added.
"That has to be replaced. I also think there are other areas of the team that need improving.
"You have to establish character, they have to be players, that is the key thing. They need that hunger to want to succeed."