The Wales international missed three months of the season with a thigh injury after an excellent start to the campaign.
"We were waiting to get some players back so it's always nice to see them back in good form," Giroud told the club's official website.
"Aaron is important right now, I think. [With] Mesut [Ozil], we will need him again and maybe he will need another full game to feel pretty good on the pitch.
"But Aaron played a great game at Hull, he's in amazing form, he's in really efficient form in front of goal. We will need everyone from now until the end of the season and it's good news for us."
Arsenal face Newcastle United in their Premier League clash later today.