What was the recent Arsenal and Celtic champions league match for?
Now, the UEFA Champions League have already drawn out the teams moments ago. What is the game for the Arsenal and Celtic recent 3-1 game for?
Yes, but why Celtic?
In the new system of the Champions League, the top 3 leagues ( EPL, Serie A and La Liga ) have only been allocated 3 automatic spots. The 4th place finisher of the leagues needs to qualify via a qualifying knockout tie with the other clubs from smaller leagues.

According the UEFA, this is to allow a fair play ground for all the clubs across Europe to compete for a place in the lucrative Champions League.