Fulham boss Claudio Ranieri led the support for "fantastic boy" Emiliano Sala as the search for the Cardiff striker continues.
The plane carrying Sala and pilot David Ibbotson disappeared over the Channel Islands last Monday, two days after the Argentinian completed a £15million move from Nantes to Cardiff.
Sala's family have led fundraising efforts to pay for a private search in the English Channel after the official search was called off by the authorities on Thursday.
And at a press conference ahead of Fulham's Premier League clash with Brighton on Tuesday, Ranieri offered his support to his former player and his family.
"Emiliano's a fantastic boy," said Ranieri, who managed Sala at Nantes.
"He's a player who puts his head where others wouldn't put their foot.
"For me, it's very, very sad. I pray for him and his family."
Cardiff return to action at Arsenal on Tuesday, when staff and supporters will wear yellow daffodils for Sala, whose family have raised £290,000 through GoFundMe donations for the private search to go ahead.
Cardiff boss Neil Warnock said: "I quite understand (sister) Romina's stance. If it was my kid, I'd want everybody looking at it forever.
"It's such a strange situation, everybody is hoping like the family.
"Football is important, relegation and things are important, but in the context of life, it just opens everybody's eyes, whether you are involved with Cardiff or any of the families."
Gunners manager Unai Emery said at his pre-match media conference: "All our thoughts go to Nantes, to Cardiff, to the player's and pilot's family, friends. Tomorrow we are going to remember them.
"We are going to play one match, remembering this situation, but also giving (hope for the recovery of) Emiliano Sala and for the pilot. Also, thoughts with his family and all friends."
Cardiff were the opponents in Leicester's first game following the death of their owner Vichai Srivaddhanaprabha in a helicopter crash in October.
And Leicester boss Claude Puel was quick to offer his support to Cardiff this week.
He said: "Of course it is another tragedy.
"We appreciated a lot the support we received from them and it is important to be close to them and support them after this awful tragedy for the club.
"It is difficult to have to try to manage this situation, and we know this situation in the past. I have thoughts for the family of the player, of course, and for the club and the fans – and the club he played for in France.
"They have had time to know him, he was a nice person and, of course, it's a difficult thing to think. We give all our support for the club and we know they can have spirit in this moment."