The 33-year-old winger has been on trial with Sunderland for the last two weeks.
Zenden is available as a free agent after his contract with Marseille expired in the summer.
“He has been here a week now and I have to say he has impressed us all, not least with his fitness levels considering the fact that he is not with a club at the moment,” Black Cats manager Steve Bruce told the Sunderland Echo.
“He also scored three times in a practice match this week and his team won 4-3 – so if ever he wanted to make a statement, that was it.”
