Per the source, Klopp has advised Lucas, Cristian Benteke, Adam Bogdan, Tiago Llori, Mario Balotelli and Lazar Markovic to leave.
Klopp responded to questions regarding potential departures by underlining that certain players will not get playing time next season and should consider their next move as a result.
“A few things will happen, I’m pretty sure,” Klopp said. “I don’t know exactly what but on both sides.
“It makes no sense to stay in the squad and be in the squad when you don’t have a real opportunity to play.
“When there’s no chance to play, it makes absolutely no sense.
“We have a few players, maybe, who want to leave us and I’m pretty sure that will happen. And one or two more players will join us from other clubs.
“It’s a long time until the 31st of August and we have to work a little bit.”
Klopp reportedly wants to trim down his squad. The Germany manager played 39 players in all competitions last season.
Lucas has been closely linked with a move to Turkey over recent weeks with Galatasaray reported to be closest to signing the Brazilian intentional.
Galatasaray have been linked with a £3 million move for the Reds according to Fanatik.
Turkish giants Besiktas are also reported to be in the race to sign the experienced midfielder and would be able to offer Champions League football next season.
Lucas was reported to be open to the prospect of joining Besiktas at the start of the month according to the Daily Star.