Le Tissier says that he has seen glimpses of potential on Rondon, but he feels that the striker's form has been very patchy so far.
"I think he's been a little bit hit and miss," the former Southampton striker said. "He got the goal at Stoke, which was important, but I've seen a bit of him so far and I'm not convinced he's worth the money they paid for him. They parted with a hefty sum for him, but it is still very early days and he's got time to improve.
"There's potential there, but he hasn't quite hit the heights yet."
Rondon has gone straight into Tony Pulis' line-up at Albion since arriving, but so far he has not hit the back of the net particularly regularly.
The Venezuelan international has scored just once in his first eight appearances for the Baggies, and that has contributed towards their struggles.
West Brom have lacked a cutting edge so far this term, and unless they can develop their attacking play then wins will continue to be hard to come by.
Pulis' side have picked up just two wins so far this season, with the team scoring six goals in their first eight fixtures.