The former Liverpool hitman is expected to be handed his Baggies debut against Manchester City on Monday.
He is likely to partner Berahino, and Pulis thinks the veteran's arrival can only help last season's top scorer.
'Rickie has a really good goalscoring record and we are hoping he will add to what Saido did last year'
Tony Pulis
"Last year we relied a lot on Saido's goals,” said the West Brom manager.
"Rickie has a really good goalscoring record and we are hoping he will add to what Saido did last year.
"He will give us another threat. Rickie is a senior player and good character as well. I think Saido will learn a lot off him."
Berahino has been linked with a move away from The Hawthorns this summer but Pulis believes he needs another season at the club to help him realise his full potential.
“He is a good player and we want to keep him and we want him to stay at the football club,” he added.
West Brom boss Tony Pulis
"I believe another year playing regular football at West Bromwich Albion will make him a better player.
"It will make him a stronger character and better player. That is my opinion.
"Saido got injured and missed the European tournament (Euro 2015), that was a massive disappointment for the kid.
"But it has given him a break and a rest so hopefully he will come back nice and fresh."
