Guendouzi was sent out on loan to Hertha Berlin after falling out of favour at Arsenal under Mikel Arteta last season, and after a rocky start, the 21-year-old has made himself a key player for the Bundesliga club.
The Frenchman has made seven appearances, scoring one goal during that time, a wonder striker against Borussia Monchengladbach to earn Hertha a point.
With Guendouzi in the team, Hertha are averaging 1.5 points per game, whilst just 0.6 points per game without him.
Hertha manager Bruno Labbadia is a big fan of the Frenchman, saying that he is a "very, very valuable" player to the team, and that Hertha "are happy that we were able to sign him".
"He's a very, very good footballer, who has a good sense of space and is technically very strong."
"Even though he's young, he gives instructions. He is not at all interested in whether he speaks the language."
According to German outlet Der Tagesspiegel, the Bundesliga side are very keen on signing Guendouzi in January on a permanent deal, with the team being impressed with their loan signing.
Guendouzi's contract at Arsenal ends in 2022, and so Arsenal may be forced to listen to offers for the France youth international as soon as possible in order to avoid possibly losing him on a free at the end of next season.
Guendouzi came under fire after the way he reacted to Neal Maupay in a game against Brighton Hove Albion last season, clutching his fellow countryman by the neck, supposedly because Maupay had injured Arsenal goalkeeper Bernd Leno intentionally.
Since then, Arteta did not favour the Frenchman, and despite lacking plenty of depth in midfield, he opted to loan him out to get some game time and to try and mature into a better player.