The Macclesfield midfielder made 39 appearances and scored four goals for the Latics during the 2005/06 season after being signed by Ronnie Moore from Lincoln.
Oldham will hold a minute's silence before the npower League One match against Southampton at Boundary Park on Tuesday night.
Hardy said: "It is absolutely tragic news and I could not believe it when I heard.
"Richard was the model professional footballer and such a likeable young man who never caused any problems for anybody.
"It is difficult to understand why anyone so young and fit should die in this way. The directors and staff at Boundary Park send their sincere condolences to Richard's family."
Source: PA
Source: PA