With players like William Saliba and Oleksandr Zinchenko out injured already, it remains to be seen how long Martinelli will be out as Arsenal go through the last two games of the season.
Arsenal forward Gabriel Martinelli might have been lucky to stay on the pitch after a dangerously-high challenge on Brighton's Kaoru Mitoma.
Mitoma continued with the game after, and it was Martinelli who had to leave the pitch after a challenge by Moises Caicedo.
Martinelli hobbled off the pitch and was later seen wearing a protective boot as Arsenal were being torn apart by Brighton.
18:33 - 14.05.2023
Further setback for Arsenal in the title race as the Gunner fall to defeat at the Emirates
Arsenal were defeated by Brighton at the Emirate Stadium as they crumbled in their chase for the Premier League title.
The Brazilian tried his best to play through the pain but was forced off in the 18th minute and replaced by Leandro Trossard.
He was then spotted wearing a protective boot on the sidelines in worrying images for fans.
Arsenal's title hopes were dealt a significant blow after they were beaten 3-0 at home.
The Gunners players kicked off well aware that Manchester City had taken a huge step to a fifth Premier League title in six seasons courtesy of a 3-0 win away at Everton.
City now hold a four-point advantage in the title race and can win the title next weekend.
Brighton started on the front foot, and despite some half-chances for the hosts, it was always the visitors who looked more likely to strike.
18:01 - 14.05.2023
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The defeat means Everton – who barely tested the Citizens - remain in the relegation dogfight.
It wasn't until the second half that things sprung into life, with Julio Enciso heading home to put Brighton in front after he was left unmarked inside the six-yard box.
Arsenal centre-back Jakub Kiwior appeared to go down clutching his ankle at a terrible time, leaving Enciso with all the space he needed to score.
The Gunners failed to respond, and Deniz Undav's lobbed strike was the dagger in Arsenal hearts, surely sparking celebrations in the blue half of Manchester.
Pervis Estupinan capped off a wonderful afternoon in second-half stoppage time by adding Brighton's third.
With players like William Saliba and Oleksandr Zinchenko out injured already, it remains to be seen how long Martinelli will be out as Arsenal go through the last two games of the season.
The defeat in front of the expectant home crowd means that City can win the title if they beat Chelsea at home next Sunday.
Arsenal can also hand City the title if they fail to win against Nottingham Forest on Saturday.