The former Chelsea forward has only recently returned to action following a five-month injury lay-off.
Havertz made his long-awaited comeback at the weekend, featuring for Arsenal against Portsmouth in the FA Cup, and is now poised to play a part in the club's latest push for silverware. His availability is a timely boost for Arteta as Arsenal continue to compete on four fronts this season.
"Obviously, we missed him a lot. A year is a long time in football but as you said, the way he's come back, he looks really fit, really confident," said Arteta.
"He's such an intelligent player that straight away he is someone who connects with the players really naturally, and you can tell how much they love him as well, because every time he was in and around the box, everyone was jumping on their seats on the bench.
"So yeah, we are so happy to have him, he's going to help us so much, and now we have to keep him fit."
Havertz joined Arsenal from Chelsea for 65 million GBP a couple of years after scoring the winning goal for the Blues in the 2021 Champions League final, a moment that cemented his place in the club's recent history.
Speaking in an interview shared on Arsenal's official website, the striker reiterated his ambition to challenge for trophies and make a decisive impact in crucial matches.
"It's a special feeling, it's amazing for myself. I'm just happy to be back with the boys and I hope I can help them as much as possible now," said Havertz.
"I think the way the boys have played the last couple of months, it was so nice even to watch from the outside, even though it's always very hard to be in a situation like this. But just to watch them was amazing and I'm very happy to be with them now."
Chelsea, now managed by Liam Rosenior, face a significant challenge against an Arsenal side full of confidence. Rosenior is searching for victory over the Gunners, a feat that eluded former Chelsea manager Enzo Maresca.
Inter will be without one of their key midfielders for the Champions League clash with Arsenal after confirming Hakan Calhanoglu has suffered a calf injury that is expected to keep him sidelined for around three weeks.
Per Mertesacker will bring his long association with Arsenal's academy to a close at the end of the current season, stepping away from the role he has held since retiring as a player in 2018.
Mikel Arteta has moved to clarify Arsenal's injury situation as attention turned to Wednesday night's Carabao Cup semi-final first leg against Chelsea at Stamford Bridge, insisting there was encouragement despite a few lingering concerns.
Liam Rosenior is preparing for his second match as Chelsea manager, with a daunting EFL Cup clash against Arsenal representing an immediate step up in difficulty from his debut fixture.
