QPR boss Mark Warburton says bringing in an experienced centre-back is a priority before the start of the new season.
Rangers have finalised their first summer signing, bringing in winger George Thomas, 23, on a free transfer after he was released by Leicester.
They have completed a reasonable first campaign under Warburton, finishing 13th in the Championship table.
But their defending, particularly at set-pieces, has been poor.
Warburton wanted to make changes at centre-back even before the departure of Grant Hall, who left the club just before the season resumed.
Aberdeen’s Scott McKenna was a target but QPR were unable agree a fee for the Scotland defender and have since cooled their interest in him.
Youngster Conor Masterson showed his potential, while academy product Joe Gubbins has been part of the first-team squad in recent weeks and came on as a substitute against West Brom for his senior debut.
But Warburton believes adding at least one experienced centre-back is a must for Rangers this summer.
“Yes, it would be, and I’m saying it because young guys have had to step up like young Conor, who at the start of the season I felt needed to go out on loan,” Warburton explained.
“You need to learn the ugly side of football, the demand for points and so on.
“He stepped up against Leeds, Swansea and Brentford and will be hoping to keep his shirt. I’ve never got a problem with that. There’s also young Joe Gubbins.
“But we need some physicality and some experience as well.”
Leistner’s future uncertain
Toni Leistner does not fit the bill as far as Warburton is concerned, although it is not yet clear where the German will be playing next season.
Cologne have indicated to QPR that they do not currently intend to take up their option to sign Leistner on a permanent deal.
West London Sport revealed soon after Warburton took over last summer that Leistner was surplus to requirements under the new manager and that the club were also looking to sell Massimo Luongo.
Leistner was subsequently dropped and stripped of the captaincy by Warburton, with Grant Hall taking over as skipper.
While Luongo left for Sheffield Wednesday, attempts to offload Leistner were unsuccessful – and he ended up regaining his place in the side.
But he remained very much out of favour with Warburton and in January he returned to his native Germany to join Cologne after West London Sport had revealed the Bundesliga club had made an approach for him.
The deal was with a view to a permanent move.
However, as things stand it appears Cologne will not be retaining the centre-back – although they have indicated that could change if they offload players.
QPR have nevertheless made other German clubs aware of Leistner’s potential availability.
Rangers are keen for him to move on and the player himself has no desire to return.
Leistner, who turns 30 next month, has a year remaining on his contract at Loftus Road.
He arrived on a free transfer from Union Berlin in the summer of 2018 and has made 65 league appearances for the R’s.