The England Under-21 international has impressed at The Hawthorns during the current campaign, scoring five goals in seven matches.
The striker's form is believed to have alerted the interest of Chelsea, but Clarke is confident that the youngster will remain with the Baggies.
"It's just speculation and the speculation is rubbish," Sky Sports News quotes the Scot as saying. "He's under contract with West Brom until the end of next season, so we've got plenty of time to sort out Saido's future.
"He's a sensible boy. He understands that all the rewards and riches come with hard work and he has to just concentrate on his football and let other people worry about his contract situation and whatever."
Berahino signed his first professional deal with West Brom in 2011 after graduating from the club's youth academy.