The Bosnian struck against the Baggies for the third time this season to hand a much-changed City a 1-0 win from a surprisingly open Barclays Premier League contest at the Etihad Stadium. The victory strengthened City's grip on second place in the table and also made mathematically certain of Champions League football next season.
Mancini had made eight changes with Saturday's Wembley date with Wigan in mind but Dzeko could have played himself into contention, and the Italian said: "Yes, could be. I am happy because he scored an important goal. We have four days to recover from this game, so could be."
He added: "With his goal we are in the Champions League and probably in second position."
Dzeko's future has been the subject of speculation and Mancini feels the 27-year-old, who has now scored 14 times this season, can improve.
He said: "In the end he has scored important goals this season. I think he can do better. For me he is a top striker but he could score more goals.
"It is clear he didn't play all the games. I think he is one of the best in Europe for me but he can do better than this year."
Yaya Toure, Vincent Kompany, Pablo Zabaleta, Sergio Aguero and David Silva were among those players rested by Mancini. Toure had been a fitness doubt after being withdrawn at half-time at Swansea last Saturday through fatigue but Mancini expects him to be fit for Wembley.
He said: "Yaya was at home to sleep. He had a problem, he was tired. Against Swansea he had a problem and we prefer he had a rest. We have four days and I need to see the players the next couple of days. I will take the last decision on Saturday.
"I thought this was a difficult game because we changed a lot of players. We needed fresh players for this game and in the end it is important that we won."
- Sports & Recreation