Aston Villa and Birmingham City have already announced their first signings of this summer transfer window, and those pre-agreed deals will soon become officialAn LED board inside Villa Park showing the Aston Villa and Birmingham City crestsAston Villa and Birmingham City have already signed players on pre-contract agreements for this summer(Image: Getty Images)

The summer transfer window opens again on Sunday – but only for ten days. Aston Villa and Birmingham City have already announced their first signings of the summer well in advance, but will still have to wait for those deals to become official.

Blues confirmed back in mid-January that defender Phil Neumann agreed terms on a transfer after signing a pre-contract agreement.

Then, a few weeks later, Villa announced the signing of Yasin Ozcan on a pre-contract agreement. Both players, however, must wait until 1 July to officially join their new clubs, despite that being an entire month after the transfer window opens this summer.

That is because their current contracts do not expire until 30 June. For the players to join any earlier than that date, Blues or Villa would have to agree to it with their existing clubs, as Real Madrid have done with Liverpool for Trent Alexander-Arnold before his contract expires by paying the Reds a reported £10million.

As such, that deal will go through on 1 June when the window opens. That date is earlier than usual because of the expanded Club World Cup.

FIFA moving the competition from its typical spot on the calendar in February or December to June and July has caused a clash with the transfer window. Business in England traditionally begins in mid-June, but that is when the tournament starts.

As such, the market opens earlier this year, allowing clubs to sign players before the competition begins. The exceptional registration period starts on Sunday and, for English Football League and Premier League clubs, ends at 7pm on 10 June.

Yasin OzcanYasin Ozcan(Image: Anadolu via Getty Images)

It will then remain shut until 16 June before reopening until 7pm on 1 September. The start-stop nature of this summer is necessary because FIFA only permits windows to be open for 16 weeks each calendar year.

Four are in January – and sometimes the first few days of February – every year, leaving a dozen for the summer. However, were those 12 weeks to run uninterrupted from 1 June, the deadline would be 24 August rather than 1 September.

Doing so would leave England out of line with the rest of Europe’s major leagues. Therefore, the brief break between the two means they will remain aligned.