The 32-year-old former England international was released by Manchester United last month and has yet to find another club.
Pulis was previously interested in signing the former Liverpool and Real Madrid striker and he is a name currently on their list.
"We tried to find out what he was doing a couple of years ago but nothing came of it - and it was a couple of years ago," Pulis told The Sentinel.
"Everyone knows Michael's pedigree and the fact he has performed with such distinction at the highest level for club and country.
"We are monitoring him, but along with about 400 other players to be honest, so it's a case of waiting to see what happens."