Manchester United fans will be hoping to see some activity at Old Trafford today. And central to Louis van Gaal's transfer strategy should be a top-class defender, according to BBC Sport's chief football writer Phil McNulty.

"If United cannot find a high-class central defender before Monday night - and Borussia Dortmund coach Jurgen Klopp scoffed at a reported interest in Germany's World Cup winner Mats Hummels - then this is undoubtedly an area opponents will see as fair game," wrote McNulty following Saturday's 0-0 draw at Burnley.

Liverpool

Image source, AFP

It has been a busy old summer on Merseyside, with Liverpool acting swiftly to bring in new faces to compensate for the loss of Luis Suarez and bolster the squad ahead of the team's Champions League campaign.

Now, it seems, is the time for a few exits.

"Players will mostly be going out rather than coming in," said boss Brendan Rodgers after his team's win at Spurs on Sunday.

"Maybe one more will come in. A few boys have been told they aren't going to get much game time so they have been given that respect early on to help themselves find a club."

Image source, AP

Could Jermain Defoe be on his way back to England? QPR are reported to be interested, external in the ex-Spurs striker whose future is a fresh talking point after his Toronto FC manager Ryan Nelsen was sacked over the weekend.

The 31-year-old could be made available for around £6.6m, and Toronto's general manager, Tim Bezbatchenko, said: "We have received multiple offers for Jermain Defoe and we will make a decision on this in the next 24 hours."

What's been happening in this window so far? Well, Manchester United broke the British transfer record when they paid Real Madrid £59.7m to sign Angel Di Maria. Mario Balotelli has a new home at Anfield and Chelsea's big-money acquisitions of Diego Costa and Cesc Fabregas are looking like astute bits of business.

Lower down the food chain, Blackpool and Crawley Town have been the busiest clubs with 17 signings while West Brom have made the most in the Premier League with 11 new faces.

Your path to a mine of transfers information is here.

Another interesting story which is bubbling away is a possible loan move for England forward Danny Welbeck. He could be on his way out of Old Trafford and on his way to Sunderland. If the Black Cats stump up a reported loan fee of £5m that is!

Image source, The Sun

What's all this chat about Colombian strikers, I hear you ask. Well, some of the morning papers are linking Manchester City, external with a move for Monaco's Radamel Falcao. However, any deal that might take Falcao to Etihad Stadium could depend on the future of Alvarao Negredo, who has been strongly linked with a loan move to Valencia. That's certainly one to watch out for.

Image source, Daily Mail

Don't want to miss any key developments? Desperate to know if your club are going to land that key player that could make all the difference?

Don't panic. You can find out exactly what we're offering and when by reading our guide to following transfer deadline day.

There will be coverage all day across television, radio and online, as well as on the red button and social media.

You can read the latest news, listen to 5 live and watch the TV coverage via the BBC Sport app on your smartphone or tablet.

It is available from Google Play for Android devices, the App Store for apple devices, and the UK Amazon Kindle Fire Appstore.

Today is all about time - the time until the transfer window closes. You have my permission to tell me off if I refer to the window "slamming shut".

The window in England, Scotland, France and Spain closes at 23:00 BST. In Germany and Portugal it's 17:00 - presumably so everyone can get home for tea-time - and in Italy it's 22:00.

Get those stop-watches out now.

Mr Lancaster:, external Just seen Falcao in a coffee shop at St Pancras station.

Image source, Reuters

First thing's first... let me tell you how you can get involved today.

We want two things from you - first of all, let us know who you want your club to sign.

Secondly, we want you to keep your eyes peeled. If you see Radamel Falcao in a Mancunian barbers shop let us know. Likewise, if you see Danny Welbeck in a Wearside chippy or even Lionel Messi walking through the arrivals hall at Heathrow Airport.

Or, more likely, if you catch a glimpse of Mario Balotelli setting off fireworks in Liverpool city centre.

Usual drill, folks: get in touch at #bbcdeadlineday,, external the BBC Sport Facebook page, external or BBC Sport's Google+ area., external

You can also text us on 81111 in the UK only - don't forget to say who you are and where you are when texting.

Image source, PA

Yep, it's that one day of the year when football managers answer their phone to journalists and the odd PPI cold-caller just in case it's an agent offering them a must-not-miss transfer deal.

The fax machine is plugged in and whirred into action, the skies above are checked for any signs of a helicopter-travelling £35m striker, and any expensive car with tinted windows is analysed to see if the passenger is a world-class Colombian forward or just the owner of the local factory.

Those car windows without tinted glass - the ones which are on a timer to wind themselves down biannually... they probably belong to Harry Redknapp.

Image source, AFP

The alarm clock went off this morning signalling the end of the summer holidays and you groaned. Back to work for some grown-ups and a return to school for the little ones.

Then you remembered. It's not all bad. It's transfer deadline day. It's Christmas Day for football fans.