The former Blackburn and QPR defender has been training with Villa for the last month after being released by Greek club Panathinaikos.
Samba, 32, played in the Villa Under-23 side which beat Wolves 2-1 at Molineux on Monday night.
“I watched Samba in the Under-23s game,” Bruce told the official Villa website.
“I’ve known him through Big Sam (Allardyce) and he’s wanted to come and train.
“There’s this notion that he’s on trial. It’s not really a trial as such.
“He wants to earn a contract and we’ve given him the platform to keep fit.
“We’ll see what happens over the next two weeks or so.”
Samba is best remembered for his time at Blackburn where he made over 150 Premier League appearances.
He joined Russian side Anzhi Makhachkala in 2012 before QPR paid in excess of £12million to bring him back to England a year later.
The centre-back spent time back in Russia at Dynamo Moscow before joining Panathinaikos.