Millwall have reportedly joined the race for QPR shot-stopper Joe Lumley, who is set to become a free agent this summer.

The 26-year-old's contract is up at the end of the season, meaning he's set to leave the club unless new terms can be agreed.

Middlesbrough are understood to be close to landing Lumley but it seems he has the opportunity to stay in London, with Football Insider revealing Millwall are also keen on him.

A product of the R's academy, the keeper has made 84 appearances for the west London club and was their first choice for all of the 2018/19 campaign and most of 2019/20 but has fallen behind Seny Dieng in the pecking order.

But what would it mean for Millwall if they signed Lumley on a free transfer?

We've outlined three potential impacts...

A replacement for Frank Fielding

It has been confirmed that Frank Fielding is leaving the Den at the end of his current contract, which expires this summer.

The 33-year-old has managed just three appearances for the Lions since joining from Bristol City in 2019 but his departure means Bart Bialkowski is the only keeper in the senior squad.

Clearly, that means Millwall need to find a replacement for Fielding and signing Lumley would be just that.

Competition for Bart Bialkowski or a long-term replacement

The 26-year-old may not just be arriving as a cover for Bialkowski, however, and will certainly be looking to capitalise on any opportunity given to him.

Bialkowski has been hugely impressive since arriving in 2019 and played every single Championship game in that period but the signing of Lumley should ensure he doesn't get too comfortable.

With the Polish keeper's contract running until next summer, Millwall could be lining Lumley up as a long-term replacement.

Allows Ryan Sandford to keep playing regularly for the U23s or go out on loan

With Fielding departing, promoting a young keeper to be Bialkowski's backup is certainly an option and U23s first-choice Ryan Sandford is the obvious candidate.

While that would be good experience for Sandford, it would likely be more useful for him to keep playing regular football – whether that be for the U23s or on loan elsewhere.

Signing Lumley should allow him to do just that.

More money to spend on other parts of the squad

Landing Lumley on a free transfer would fill a gap Millwall need filling and likely do it cheaply.

Though Boro are also keen, the 26-year-old's current contract with the R's sees him earn £7,000 per week – so even if the Lions have to pay a bit more than that as well as a sign on and agency fee it shouldn't be too much.

That's a boost as it would allow them to invest more money improving other parts of the squad.