Leicester's players have been visibly affected by the incident and have spent Monday and Tuesday attending commemorative events to pay tribute to Vichai, the club's popular Thai owner whose helicopter spiraled out of control as it left the King Power Stadium following a Premier League game against West Ham on Saturday.
Vichai's heavy investment after buying Leicester in 2010 transformed the unglamorous club into shock Premier League champions as 5 000-1 outsiders in 2016.
"As a mark of respect, players will wear black armbands at all Premier League fixtures this weekend".
Cardiff chief executive Ken Choo pledged to provide assistance to the visitors.
He told the club's website: "Following Saturday evening's awful events at King Power Stadium, the thoughts and feelings of Leicester City FC are at the forefront of our minds".
Pearson's new club OH Leuven, where Vichai also acted as chairman, announced they had postponed Wednesday's fixture against Lommel in the Belgium second division.
Thai businessman Srivaddhanaprabha oversaw Leicester's remarkable Premier League triumph in 2015-16.
The season after winning the title, Ranieri was sacked as Leicester manager in February 2017 with the club one place above the relegation zone.
Former Leicester City manager Nigel Pearson said he "could not have wished for a better boss" than late chairman Vichai Srivaddhanaprabha.
"This most definitely ensured the belief that sporting miracles can happen".
Leicester have also opened a book of condolence in memory of Vichai in a marquee at the stadium, while the City Hall and County Hall will light up in blue this week to honour Vichai.
The Foxes confirmed the book will remain open for 14 hours every day "for the foreseeable future". People unable to visit the stadium can leave a message in an online book of condolence via the club's website.
The EFL Cup tie between Claude Puel's side and Southampton, scheduled for Tuesday, was consequently postponed.
The UK's Air Accidents Investigation Branch (AAIB) said it had recovered the flight data recorder and would continue to investigate the cause of the crash.
Leicester goalkeeper Kasper Schmeichel, who was present at the scene of the crash on Saturday, was in tears as floral tributes were laid inside and outside the King Power Stadium on Monday.