The former Barcelona man seems likely to join the Premier League club, where he will likely be used as a squad player in the middle of the park...
The Black Cats' boss ran the rule over the 33-year-old former Barcelona star and is now set to offer him a full-time contract.
Zenden left Marseille at the end of last season and has been looking for a club over the summer. He looks set to return to the north east of England after an earlier spell with Middlesbrough.
"I've known 'Bolo' for a good few years, he picked the phone up and asked if he could come over and he's done very, very well," Bruce told the club's official website.
"He gives us a little more experience and it's in the back of my mind that we're very short of numbers in the middle.
"We only really have Jordan [Henderson], Lorik [Cana] and Lee [Cattermole], and the latter two will pick up a few yellow cards.
"You don't play for Liverpool, Barcelona and Marseille if you haven't got pedigree, and the lad's in tip-top condition for his age.
"I will have a conversation with Bolo towards the end of the week and we'll take it from there."
Lucas Brown, Goal.com