Zenden is a free agent after his contract with Marseille expired at the end of last season.
“Sunderland would like short term to strengthen the midfield and Boudewijn is a serious candidate,” Zenden’s agent and father, Pierre, told Voetbal International.
“In the past months he has been very strict with himself and has worked six days per week to keep in shape.”
“Sunderland know who he is and what he can do so he has no need to prove himself.
“They want to see him doing it and it just despends on medical tests.”