Reds boss Brendan Rodgers looks set to revamp his backline in the summer, with veteran Jamie Carragher hanging up his boots and Martin Skrtel linked with a move away.
Swansea skipper Ashley Williams is reportedly on the Anfield club's radar, although it appears Rodgers is prepared to cast his net wider in the search for defensive recruits.
Bruno Hubner, a director at Eintracht Frankfurt, has revealed the Merseysiders have made a tentative approach for Peru international Zambrano.
The 23-year-old came through the youth academy at fellow Bundesliga outfit Schalke, though he left the club in 2010 for St Pauli in order to secure regular first-team football.
After two years with the Hamburg-based club he moved to Frankfurt last summer, playing his part in a fine campaign for Armin Veh's men to date.
The club are currently riding high in fourth place in the Bundesiga after earning promotion from Bundesliga 2 only last season.
"There's interest from Liverpool in Carlos Zambrano," said Hubner. "They have asked about him, but there has not been an offer yet."