"It's one big family and we're always going to fight for each other".
Welbeck was rushed to hospital after the match and Emery reckons he has broken his ankle. "We are thinking how he can help us in the future".
Emery said after the game: "Lichtsteiner's injury changed our idea on the match, we wanted to change for Eddie Nketiah and give another chance for the striker".
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", the Spaniard told a media conference.
The 6-foot winger has been a revelation since leaving Angers for Lille in 2017, scoring 14 goals in all competitions last season before playing a starring role this term. But when the match finishes, the first thing they did was ask for him.
"He's always encouraging me to be positive with the ball, always encouraging me to work hard off the ball for my team as well". He is a very good person, his commitment to us is very big. "We don't want it, but this is our profession".
The potential absence of Welbeck leaves Arsenal short of options in the attacking third of the pitch as Alexandre Lacazette and Pierre-Emerick Aubameyang remain the only genuine forwards in the squad, although it remains to be seen whether the Gunners hierarchy hand manager Unai Emery funds to sign new players during the January transfer window.
The 27-year-old has been riddled with fitness problems since joining the Gunners from Manchester United for a fee of £16million four years ago.
Supporters have taken to social media to say how "heartbreaking" it is while TV presenter and lifelong Arsenal fan Piers Morgan was among those to say how "gutted" they are for Welbeck.
That all means that if they are victorious at the Emirates Stadium on Thursday evening, Arsenal will be through to the knockout stages as group winners, despite having two matches left to spare.