"This could be a break of something in the ankle", stated Emery. "It's a different injury to others". Now he is at the hospital. "We are thinking how he can help us in the future".
The incident seemed to affect both sets of players for the rest of the game, with little in the way of goalscoring opportunities.
'The worst news tonight is these injuries - we think serious injury.
Guendouzi will partner Granit Xhaka at the base of Arsenal's 4-2-3-1 and they will look to dominate the Sporting midfield.More news: Meg Ryan announces engagement to John Mellencamp
"Then the players concentrated on the match and we forgot".
Caretaker Sporting boss Tiago Fernandes said: "The players did exactly what I asked them to do".
He said: 'He is a very good person, his commitment with us is very big. "You don't want it to happen but this is our profession".
Pierre-Emerick Aubameyang is expected to take over the mantle of leading the Arsenal attack this week and could start in place of Alexandre Lacazette.More news: Bourke Street stabbing: One dead, man arrested in Melbourne
The 27-year-old has overcome serious issues in the past, missing large chunks of his career with knee problems.
Welbeck landed awkwardly after leaping in the air to meet a cross just after the half hour mark against Sporting, and needed oxgyen before being stretchered off the pitch.
This latest setback comes on the day he was named in Gareth Southgate's latest England squad for the forthcoming games against the United States and Croatia.
But Arsenal could not take advantage as Aubameyang blasted the resulting free-kick well over the crossbar.More news: New Acting Attorney General is a GOP Loyalist from Iowa
And Flamini, who played for the Gunners for seven seasons across two spells with the club, believes the difference in Emery's Arsenal is evident in how hard the team are working to win the ball back.