Real Sociedad are offering to exchange Inigo Martinez shirts for free with their fans.

Martinez has upset La Real's support with his decision to leave for rivals Athletic Bilbao.

After Aymeric Laporte left the Bilbao club for Manchester City, they moved to replace him.

Now, any fans who own a jersey with Martinez's name and his No. 6 can return it for a new one for free.

The club confirmed the news on social media with a short headline, simply saying: "It is already history."