Bender stays behind in London for surgery
Bender, 22, whose twin brother Lars was in the Bayer Leverkusen side who beat Chelsea 2-1, was caught by a flying boot in the face from Arsenal defender Thomas Vermaelen after 20 minutes of their Group F match.
Dortmund's manager Jurgen Klopp told reporters that his player was not well enough to fly home with the rest of the squad.
"He will have an operation in hospital in London tomorrow morning, he cannot fly home now," Klopp said.
Less than five minutes after Bender was stretchered off the Emirates Stadium pitch, Dortmund also lost Mario Gotze, one of the brightest prospects in European football, with a knee injury.
"He has a bruised muscle around the knee, and although he should be OK, we will have to wait and see," Klopp said.
"We started well, but after those two injuries in four or five minutes, it really hurt us and gave Arsenal a lot of confidence."