Players from Girona and Feyenoord this evening might be left wondering how one linesman can be in two places at the same time.
But if they had checked the match programme ahead of the key Champions League clash they would know they were looking at two different people - Swiss identical twins Marco and Benjamin Zurcher.
Clearly inseparable, the pair joined referee and compatriot Urs Schnyder as assistants at the Estadi Municipal de Montilivi in Girona this evening as the Dutch side earned a 3-2 win.
The siblings, both 38, work as linesmen in the Swiss Super League, Swiss Challenge League, the Nations League, and the Champions League and, unsurprisingly, often come as a duo.
Standing in the tunnel ahead of the match in Spain, the twins had their game faces on, sporting extremely similar expressions as they flanked Schnyder with the two sets of players standing behind.
Swiss identical twins Marco and Benjamin Zurcher joined referee Urs Schnyder as officials
Antoni Milambo's finish helped Feyenoord to a valuable 3-2 win over Girona tonight
The Zurchers are members of a very select group of twins who have shared a football field together, with the De Boer brothers arguably the most successful of the exclusive bunch.
Frank and Ronald followed each other to a whopping five different clubs - Ajax, Barcelona and as well as Qatari outfits Al-Rayyan and Al-Shama. The Dutch duo won 33 trophies including the Champions League.
Manchester United fans will remember Fabio and Rafael da Silva - the Brazilian brothers who signed from Fluminense together in 2008. The identical twins lifted the Premier League trophy with the Red Devils in 2009 and 2011.
On the pitch itself, Girona and Feyenoord put on an entertaining display in the second round of Champions League matches.
The Zurchers are members of a very select group of twins who have shared a football field, with the De Boer brothers (Ronald, left, and Frank, right) arguably the most successful
Manchester United fans will remember Fabio (left) and Rafael da Silva - the Brazilian brothers who signed from Fluminense together in 2008
The Dutch visitors clinched a 3-2 victory after Czech defender Ladislav Krejci became the second Girona man to turn the ball into his own net.
The 79th minute goal came minutes after former United man Donny van de Beek struck an equaliser for the Spanish outfit in the 73rd minute.
David Lopez had given the home team the lead before a Yangel Herrera own goal quickly brought the game back to level terms. Antoni Milambo then put Feyenoord in front towards the end of the opening period.