The 2015 summer transfer window is about to slam shut, but which last-minute signings could still be made? IBTimes UK sports editor Nick Howson previews the players who may be make a move before the window closes.

Live Coverage - Transfer deadline day

David de Gea to Real Madrid deal collapses

One player whose plans of moving appear dashed is Manchester United goalkeeper David de Gea. The 24-year-old Spain international was set to sign for Real Madrid for £29m ($44.5m), with Costa Rica custodian Keylor Navas moving in the opposite direction.

But after the necessary paperwork was not submitted in time for the Spanish transfer window deadline, the move now appears to be off.

Anthony Martial, Saido Berahino and Victor Wanyama all set to move

Uniteds De Gea deal might have collapsed, but there is still one piece of business they are expected to complete, the £36m signing of striker Anthony Martial from Monaco.

Aside from Manchester United, Tottenham are set to be the team most active on deadline day. Spurs manager Mauricio Pochettino has already confessed his love for West Brom striker Saido Berahino, so expect a final offer to be made to the Baggies.

The North Londoners have also been linked with Southamptons wantaway midfielder Victor Wanyama, although Saints boss Ronald Koeman insists no more of his players are for sale.

Chelsea and Arsenal could spring a surprise

Manchester City and Liverpool appear content with their squads, but their main rivals in London could both make a surprise last-minute signing on deadline day.

Jose Mourinho has made it loud and clear that he feels the Blues need another centre-back to protect their vulnerable defence. Bids of up to £30m for promising England international John Stones have been swatted away by Everton, meaning that the club might have to find another option to bolster their back line.

Arsenal, on the other hand, have been linked with a host of strikers all summer. While a marquee move for the likes of Karim Benzema, Zlatan Ibrahimovic or Edison Cavani seems unlikely, do not be astounded if Arsene Wenger makes a final foray into the transfer market before the window closes.