Chelsea dominated the first half and took the lead through Joao Pedro just before the break but completely capitulated in the second.
Cucurella, 27, was replaced by Malo Gusto in the 69th minute after asking to be substituted due to an issue with his hamstring.
Asked why Cucurella came off, Maresca said: “Because he was complaining about his hamstring. We don’t know if it’s an injury now or not. He asked for the change.”
The defender is now set to undergo scans to determine how serious the injury might be ahead of their game against Bournemouth on Tuesday (December 30).
