The £27m January signing has followed up a scoreless run of four matches with four goals in his last three games, most recently netting a brace in the 2-1 win over Stoke City.
Tosun has put his upturn in fortunes down to the guidance of Ferguson on the training ground, and the former Everton striker believes that the only way is up for the Turkey international after adapting to his new surroundings.
"He's settling in well," he told Sky Sports News. "I think it took him a bit of time to adjust to the Premier League but he's looking good.
"We're obviously made up that he's scored a few goals now. Hopefully that continues. He can be a success if he keeps on working hard, we keep on giving him the supply. I think he can score goals for us."
Tosun netted 14 goals for Besiktas in the first half of 2017-18 before making the mid-season switch to Merseyside.