The Netherlands international has spent nearly two seasons on loan at the Liberty Stadium from Villarreal and scored twice against Norwich City to impress his manager.
The Netherlands international netted twice in the hosts' 3-0 win over Norwich City, and Monk knows the importance the loanee has on his side's success.
De Guzman, at the Liberty Stadium for a second successive season, has scored four goals in the 2013-14 campaign but his all-round performances have most impressed Michael Laudrup's successor.
"He's a very good player," Monk told the press. "He suits the way we play, he can play in quite a few positions and is technically very good. You've seen what he offers to the team, and those are the sort of players you want at your club."
"For me, he was our man of the match [on Saturday], he epitomized everything that was good about us - his movement, his desire to get the ball back and to get two goals. He was very good value, I thought he drove the team on," Monk continued. "He enjoys it [here], hopefully that's an attraction [for him to stay]. The fans like him very much. It would be an important signing for the club."