Villarreal players presented Borussia Dortmund with a signed Sebastien Haller shirt prior to their pre-season friendly.
In a touching display of solidarity, Villarreal gave the Bundesliga side the shirt dedicated to Haller, following his shock testicular tumour diagnosis earlier this week.
The LaLiga side went on to win the game 2-0 thanks to goals from star striker Gerard Moreno and Nigerian international Samuel Chukwueze as Dortmund lost their last game before the start of their season.
Having started Niklas Sule, Mats Hummels and Nico Schlotterbeck in a back three for the first time, Edin Terzic's side fell victim to defensive errors as they finalised their preparations for the 2022-23 season.
Spanish forward Moreno opened the scoring on the stroke of half-time after beating an offside trap before finishing past Alexander Meyer.
Chukwueze then doubled the ascendancy after the interval by steering the ball past the 'keeper from outside the Dortmund penalty box.
But the game was understandably about more than the result, as exemplified by the Spanish side, who echoed the messages sent out to Haller by the majority of the footballing world.
The Frenchman's former team-mate Declan Rice told SkySports: 'Everyone at West Ham is behind him and I think everyone in football is as well, you can see what type of character he is.
'He's like a big friendly giant, he's so smiley. When he came here he was so enthusiastic, he wanted to work hard and score goals.
'It didn't work out for him [at West Ham] but what he's done at Ajax and now that he's got his move to Dortmund is a credit to him.
'I saw on his Instagram that he's had one operation already so his recovery is underway which is special.'
Several clubs have taken to Twitter to show their solidarity with the French striker, including former club Ajax.
Haller took to social media to share his progress following the first stage of his treatment.
Posting a picture from his hospital bed on Thursday, a smiling Haller tweeted: 'Hello everyone, I wanted to let you know that Step 1 has been completed!
'I would like to thank the @BVB (Dortmund) and the medical team who were exceptional with me.
'A big thank you also to all the nursing staff of the hospital for their support - benevolence.'
The 28-year-old Ivory Coast international joined Dortmund from Ajax earlier this month for a reported £27million.
He signed a four-year deal, after scoring 32 goals in 36 appearances in all competitions for the Dutch club last season.
Haller spent one and a half seasons at West Ham, making over 50 appearances, before the Hammers sold him to Ajax for £20.25m in January 2021.
