The Blues have struggled this season but Bilic believes they will turn things around.
The Blues put an end to a dismal run of results with a 2-0 win over Aston Villa last weekend but were held by Dynamo Kiev during the week and are not yet back to their fluent best.
A trip to the Boleyn Ground to face an in-form Hammers team is next up for Mourinho's men and Bilic believes Chelsea may have reached a turning point.
“Well, I see them finishing in the top four,” he said, in quotes published by the Daily Star.
“As I said, the last couple of games they did well. They won against Aston Villa, it was not a beautiful game but he said they are back to basics and now they don’t have to care about how much possession they have.
“They needed points and they did it with a clean sheet because they haven’t done that regularly this season.
“I was quite impressed with the game against Dynamo Kiev, it was like back to the Chelsea we are used to watching regularly,” he added.
Saturday’s encounter is finely poised, with West Ham’s excellent form this season mainly coming away from home, and Chelsea back to winning ways.
Despite playing at Upton Park, Bilic’s men will likely treat the clash as if it were an away game and look to punish the Blues on the break.
Their performances against the big boys this season have been excellent and there is no reason that won’t continue against Jose Mourinho and co. tomorrow.