Ahly coach Koller during the Cairo derby game against Zamalek. Photo: Ahly s official website
Sherif came off the bench to score two superb goals and round off an impressive win for Ahly.
He earlier replaced Mahmoud Kahraba, who scored against his ex-club to open the scoring one minute past the hour mark.
Sherif has been heavily criticised for a number of below-par displays this term but he looked a rejuvenated figure against Zamalek to take his tally to six goals in the derby.
"Sherif regained his form today. I spoke with him and we watched together replays of his previous games and goals to give him more confidence," Koller told the post-mach news conference.
"I am really happy for him because he was able to relieve pressure on himself. I hope today's brace would mark his return to form."
After a dull first half, the match sprang into life after the break when Kahraba opened the scoring following a defensive lapse on 61 minutes.
"I spoke with the players during the break and I asked them to be calm and concentrate in their passes behind Zamalek's defence to create more scoring chances," Koller added.
Ahly missed the services of midfielder Amr El-Sulaya as well as defenders Yasser Ibrahim and Mohamed Abdel-Monem due to injuries.
They joined long-term absentees Akram Tawfik, Karim Fouad on the sidelines.
"The 3-0 win over Zamalek shows that we haven't been affected by the big number of absentees," Koller said.
Leaders Ahly, who top the table with 34 points from 14 games, increased their lead over fourth-placed and defending champions Zamalek to eight points. Future are second on 30 points, with Pyramids third on 27.
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