The result sees Arsenal qualify from their group.
But the result was overshadowed by Welbeck's situation, who appears to have suffered a serious ankle injury.
Iwobi said, "We knew it was going to be tough as when we played them away it was not easy. It is a decent result but we have to keep the focus into the next games.
"It is mentally challenging [playing on after a team-mate is badly injured] but sometimes it comes with the game, and Danny [Welbeck] has had a lot of injuries. We wish him the best and will keep on encouraging and motivating him to get back.
"We have to give credit to Sporting and they were compact but we lacked a bit of composure, even from myself.
"It was sad as Pierre [Aubameyang] was through, but it was a smart challenge from [Jeremy] Mathieu and unfortunate for us as we weren't able to get the goal.
"We will go again at Wolves which we know won't be easy as they have started the season well."