Martinelli suffered ankle ligament damage after a heavy challenge from Arsenal transfer target Moises Caicedo during last weekend’s listless 3-0 home defeat by Brighton that effectively ended the Gunners’ title charge, leaving the Emirates wearing a protective boot.
The Brazilian winger still requires further assessment to determine exactly how long he will spend on the sidelines, with Arteta describing the injury as “pretty nasty”.
Martinelli will play no part in Saturday’s trip to relegation battlers Nottingham Forest - which will see Manchester City crowned champions again without kicking a ball if Arsenal fall to another loss - or the home clash with Wolves on the final day of the Premier League season.
That is also the case for versatile left-back Zinchenko, who did not play at all against Brighton due to a calf strain sustained in the previous 2-0 win over Newcastle on Tyneside.
“They are both out for the rest of the season,” Gunners boss Arteta told reporters on Friday.
“Gabi [Martinelli] is a pretty nasty injury, we need to assess in the next week how long he will be out for and with Alex [Zinchenko] it’s a calf issue.”
Arsenal already have three other players ruled out for the season as things stand, with key centre-back William Saliba having failed to make progress in his recovery from a lower back injury suffered against Sporting Lisbon in the Europa League back in March.
Fellow defender Takehiro Tomiyasu and veteran midfielder Mohamed Elneny are also long-term absentees with respective serious knee injuries that required surgery.