De Guzman netted from the penalty spot and then added a second in the dying minutes as Swansea won their first major trophy in 101 years of history with a 5-0 win at Wembley.
The midfielder joined Swansea on loan from relegated Villarreal in the summer and has enjoyed a fine season at the Liberty Stadium, so much so that he was rewarded with his debut for Netherlands in a friendly international against Italy in February.
And given he enjoys working under Michael Laudrup, who previously managed him at Real Mallorca, De Guzman is understandably keen to hold talks over a permanent deal.
"I am here and I am happy to be here," De Guzman told Eurosport-Yahoo! "Everyone knows that.
"If the talks are here then my ears are open."
De Guzman, 25, was also full of praise for Laudrup after the Dane secured a wholly unexpected League Cup triumph for the Welsh club by improving on the work done by Brendan Rodgers last season.
"He's very laid back." De Guzman added. "He lets you make your own choices. He lets the players be free and I think players really, really like that.
"Swansea played good football even before he came here, under Brendan Rodgers, and he obviously didn't need to change the philosophy. He just put a bit of accent on it and brought in a couple of reinforcements.
"I think playing Swansea football is what his coaching was like so it was very easy for him to adapt and also for the players too."