Whether Welbeck will play again in 2018/19 remains to be seen.
As Arsenal wait to find out the extent of the injury, Emery said his players were anxious about their team-mate after the final whistle following a likely serious injury. "We will know [more] about his injury tomorrow".
The 27-year-old has overcome serious issues in the past, missing large chunks of his career with knee problems.
"Now he's at the hospital and the news is at the moment we are going to wait, but we think this is a serious injury".
What have Arsenal announced about Danny Welbeck's injury? A good lad and a good friend. We wish him all the best in his recovery.More news: Dead brothel owner wins election for Nevada legislative seat
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Welbeck is out of contract at the end of the season so the Sporting Lisbon stalemate might end up being his final appearance for the club.
The game was then stopped for several minutes after Welbeck contested a header with Gaspar before appearing to suffer an ankle injury on landing.
The incident knocked the wind out of Arsenal's sails but Welbeck's replacement Aubameyang hit the crossbar as the visitors offered very little in terms of an attacking threat. But when the match finishes, the first thing they did was ask for him.
Henrikh Mkhitaryan was singled out by a number of supporters as one of those that deserved criticism for his display in the game. The biggest topic of discussion was Danny Welbeck, who looked to really injure himself following an attempt at goal.
"Structures within the ankle which could [be] injured [are] the medial, lateral, anterior & posterior ligaments, tibia, fibula & talus bones as well as chondral surfaces".