Arsenal have confirmed that Bernd Leno suffered a sprain to his right knee against Brighton, while Gabriel Martinelli is set to miss "months" of action with a knee injury.
Leno was hurt during Saturday's clash after contesting a ball with Brighton striker Neal Maupay, and had to be taken off on a stretcher as Emiliano Martinez came into the action.
In his absence, Arsenal took the lead through Nicolas Pepe but later faltered, with Lewis Dunk and Maupay himself scoring to secure three points for the relegation-threatened Seagulls.
The Gunners initially feared that Leno may have suffered damage to his cruciate ligament, with manager Mikel Arteta stating after Saturday's game: "Bernd’s injury doesn’t look good, we have to assess it tomorrow to know what’s happening.
"We don’t know [if it’s a cruciate injury], he is still in some pain. We will have to wait until tomorrow at least to see how bad the damage is."
On Tuesday, though, the club released a medical update on several injured players, with good news to share about their No.1.
"Right knee. Positive news after detailed assessments," the bulletin posted on the club's official website said of Leno's condition.
"Sustained moderate ligament sprain during Brighton & Hove (a) on Saturday. Aiming to return to full training in four to six weeks."
Arsenal also welcomed back Sokratis and Granit Xhaka, who have both resumed full training after suffering a thigh strain and ankle sprain respectively.
But the north London club are bracing themselves for bad news over young sensation Gabriel Martinelli, who pulled up with a knee complaint during training.
"Left knee. Sustained cartilage injury during training on Sunday. Further assessments and tests to take place in forthcoming days," Arsenal signalled in Martinelli's assessment.
"We had some really bad news against yesterday [Monday]. In training in the last action he got hit by another player," Arteta told reporters on Tuesday.
"He’s damaged his knee, the doctors are assessing the extent of the injury but it’s not looking good at all.
"How bad? We don’t know, but he’s looking at months.
Martinelli is set to join the likes of Pablo Mari, Lucas Torreira and Calum Chambers in missing the rest of the 2019-20 campaign, while Leno is also unlikely to feature again with Arsenal's final match of the Premier League campaign five weeks away.
"If two players bang each other, or if what happens with Pablo on his own and a lot of others we’ve had in recent months, they are not muscular injuries. They are more traumatic injuries," Arteta added on Arsenal's injury misfortunes.
"But again, we’ve been really unlucky with that and we have to deal with it."
Arsenal are back in action on Thursday, when they travel to St. Mary's in order to take on Southampton before resuming their FA Cup campaign three days later away to Sheffield United in Sunday's quarter final.