Why is there a minute's silence before Manchester United's Champions League game against Atletico Madrid?

A minute's silence will be observed ahead of kick-off in Manchester United’s UEFA Champions League clash against Atletico Madrid tonight. It follows the passing of Ana Merodio Borja, the mother of Atletico captain Koke and academy coach Borja Resurreccion. Atletico confirmed the news in an official statement on Tuesday, revealing that their skipper's mother had passed away in Madrid earlier that morning. Both sides and supporters inside the ground will unite before the referee's whistle to pay their respects. Koke is one of the Spanish club's defining figures of the modern era.