We have heard this story before, of course. Last summer it seems Liverpool were open to offers for him, even when he broke into the team approaching the midway point of the season - and was demonstrating his importance to the side during a reasonably good run - rumours persisted that the Brazilian could be waving farewell to Merseyside.
The big thing is that Lucas seems to be the only player at the club who you would regard as a specialist defensive midfielder.
Unless Liverpool have someone else in the pipeline, and should the manager wish to operate with a single holding midfielder, who would fit the bill out of the current members of the squad?
Allen seems to divide opinion. In the eyes of many he is too small to deal with the demands of playing the sitting role and getting involved in the physical aspect of the play, while other critics will say if he isn't doing anything wrong then he isn't contributing much in the first place.
The point with the former is that a lot of the better holding midfield players have a degree of presence - though some will look at the likes of Claude Makelele and Michael Essien and say they weren't the biggest of players, but they embraced the physical demands of their role.
Allen seems far more at home further forward, on the side of a diamond midfield or in a partnership. So what about Emre Can?
If people cast their minds back to October, the young German was given the job of holding midfielder against a struggling Queens Park Rangers side - at half-time he was moved from that position and Steven Gerrard returned to the role as he struggled when Bobby Zamora was dropping into deeper positions and easily getting the better of the German.
But Can was relatively successful when playing on the right side of a defensive three later on in the season, and has been quoted, in 11 Freunde, hinting that Brendan Rodgers wants him in midfield - and fans will hope he will never have to be used as a right-back ever again.
But the experience of playing in a deeper role for the side could stand him in good stead to learn a role of a sitting midfielder, and with energy in there that Jordan Henderson and James Milner have, he can provide the drive and bursting runs from deep to great effect to cover for him should the Reds get hit on the break.
One must take into account here is that he is still young, and fairly untested since that trip to Loftus Road when the side had its back against the wall, and it would take a degree of time for him adapt and grow into the role properly.
The other option, of course, is to buy another midfield player, someone used to the role, because with a Liverpool side that still has defensive vulnerabilities, it would have to be a good one.
Regardless of who the person is to fill the post, Liverpool need a competent defensive midfielder. If it's not Lucas, then Brendan Rodgers needs a good plan.