Celtic manager Neil Lennon has taken Croatian goalkeeper Stipe Pletikosa on trial.
But Lennon also remains keen on Scotland keeper Craig Gordon, who is currently injured at Sunderland.
Last season Pletikosa, 32, went on loan from Spartak Moscow to Harry Redknapp's Tottenham but made only one appearance for them.
"Harry Redknapp was raving about Pletikosa so we'll have a look at him," said Lennon.
Pletikosa started his career at Hajduk Split before moving to Shakhtar Donetsk for four years, then Spartak Moscow.
Gordon has a year left on his Sunderland deal and has been told he will have to win back the jersey when he returns from knee surgery.
Lennon has admitted the former Hearts player might be out of Celtic's price range.
"The problem with Gordon is he's not fit until October but we can still make an enquiry," he said.
"He's a quality keeper and he's on our list."
But Lennon says he is untroubled at the prospect of playing current number one Lukasz Zaluska.
"I'd have no qualms about starting the season with Lukasz," he added.
"It was a step up when [Artur] Boruc left and he didn't handle that as well as we would have liked.
"We've spoken to him and explained that was a disappointment to us but he looks a lot more assured and confident now and physically he is a lot better."