Spanish outlet Sport, as quoted by the Daily Express, is reporting that the Reds are keen to land the veteran goalkeeper, who is currently at FC Porto.
The World Cup winner would be available on a free transfer at the end of the season and Liverpool FC are thought to be on the lookout for reinforcements between the posts this summer.
The same story says that Liverpool FC will definitely have a new number one between the posts next season, with neither Loris Karius nor Simon Mignolet particularly impressing this season.
The 36-year-old Casillas has made 22 appearances in all competitions for FC Porto this season and he kept a clean sheet at Anfield during the return leg of their Champions League quarter-final clash against Liverpool FC last month.
Liverpool FC are likely to be linked with a host of players in the coming weeks and months as Jurgen Klopp looks to bolster his squad and assemble a team capable of winning the title next season.
The Reds will return to Premier League action on Saturday lunchtime when they take on Everton at Goodison Park.
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