Chelsea earned just their fifth Premier League win of 2025 thanks to late goal from Tyrique George and Pedro Neto.
The West London club climbed back into the top five as they race against the likes of Aston Villa, Newcastle United, and Man City to secure Champions League qualification.
Maresca rolled the dice at half-time, bringing on Gusto, 21, for captain Reece James, but the Frenchman was unable to finish the game.
Gusto pull up with what appeared to be a hamstring injury, forcing Maresca to replace him with Tosin Adarabioyo for the final minutes of the game.
Speaking to the press after the game, the under-fire Italian provided a blunt update regarding the right-back’s injury.
He said: “Not a good one. A muscular problem. Unfortunately, it looks like a muscular injury.”