Sunderland are having a look at former Leeds defender Ian Harte and Samuel Kuffour as Roy Keane looks to bolster his defence.
Ghana international Kuffour is currently on the books of Serie A side Roma but spent last season on loan at Livorno.
Keane told the club's official website: "They are training with us for a few days.
"We are having a look at them and it's good for them to look at what we are doing here, but there's no chance of them signing before the weekend."
