Riquelme has not played for Boca since they lost the Copa Libertadores final in July, but has not formally retired.
Speaking at the press conference to mark the start of his third stint in charge, Bianchi shared his belief that the former Barcelona and Villareal star could still contribute to the team at the age of 34.
"We'll see what the chances are for Roman to come back," Bianchi said.
"The decision is Roman's, everyone is the owner of their own decisions. I'll speak with him and see if he is prepared to return," added the 63-year-old.
"I know what Roman can give the team, but until I meet with him I can't say anything else."
Meanwhile, club president Daniel Angelici told Infobae: "If there's anyone who can make Riquelme change his mind, that person is Bianchi."
Bianchi was officially unveiled on Wednesday at the club's Casa Amarilla training complex, where he signed a three-year deal.
The former Atletico Madrid trainer won four Argentine league titles, three Copa Libertadores and two Intercontinental Cups during his previous spells at Boca between 1998 and 2004.
Riquelme, who has promised to make a decision on his future this month, shared in six of those successes.