The Blues are suffering a series of injuries that has undermined the club’s form contributing to a run that has seen them knocked out of both domestic cups and fall to tenth in the Premier League.
Pulisic suffered a knee injury and Sterling hurt his hamstring strain 10 days ago at home to Manchester City.
Speaking ahead of a crucial league match away at Fulham on Thursday, Potter delivered an update on the players that he has available.
He said: “Christian’s going to be out for a couple of months we think. Hopefully, it will be less, but that’s the timeframe there.
“We think Raheem will be out for less time than Christian. We’re still evaluating the actual extent of it, but hopefully, it will be less than that.”
Pierre-Emerick Aubameyang will return after missing the 4-0 defeat away at City on Sunday.
Ruben Loftus-Cheek and Ben Chilwell won’t be fit for the trip to Craven Cottage but are the next two the Blues expect to have back.
“We’re making progress,” he added. “Ruben’s getting closer, Ben Chilwell getting closer.
“Reece was out on the grass today, not training with the team but training on his own. N’Golo’s had his first couple of days out training on his own as well, but he has still got a long, long way to go before he can play.
“So it felt a bit more positive obviously to see those guys out there training and it gives people a bit of a lift.”
It remains unclear when Wesley Fofana or Edouard Mendy will return while Armando Broja is expected to be out for the season after having major surgery on his knee.