Riquelme is reportedly being pursued by a number of Brazilian sides after ruling out a return to Boca Juniors last week, reports Xinhua.
"I don't know if he will be recruited. It is the directors who look after those matters but if that's the case he will be welcome here," Deco said on Wednesday.
When asked whether the reigning Brazilian champions could accommodate the 34-year-old in their midfield, Deco replied: "I don't see any problem. Players adapt easily to having quality players around them."
Rival Brazilian clubs Atletico Mineiro and Palmeiras are also interested in the Argentine.
Atletico playmaker Ronaldinho has reportedly called Riquelme in a bid to convince him to join the Belo Horizonte outfit.