Mathieu Debuchy wasn't the obvious culprit but the difference in athleticism between he and starter Hector Bellerin was crucial to Spurs' opener in the 1-1 North London Derby.
Arsenal starters vs Lyon: Martinez, Debuchy, Mertesacker, Koscielny, Gibbs, Coquelin, Ramsey, Oxlade-Chamberlain, Ozil, Iwobi, Giroud
Arsenal will be without the services of French full-back Mathieu Debuchy for the visit of Swansea on Monday as the defender continues to struggle with a muscular problem.
Mathieu Debuchy's absence has seen Hector Bellerin's career take off earlier than anyone likely would have predicted and now that the France international is healthy, he faces a fight to regain his spot in the starting eleven.
Mathieu Debuchy has resumed training with the first team and suffered no setbacks but Arsene Wenger refused to commit to how he might use the France international against Liverpool in Week 31 action.
Arsene Wenger confirmed earlier reports that Mathieu Debuchy would be out for three months due to the shoulder injury suffered against Stoke City on Sunday.
Mathieu Debuchy is facing another lengthy spell on the sidelines with his shoulder injury but just how long is still up in the air.
Mathieu Debuchy had to exit Arsenal's match with Stoke City today as he landed awkwardly after a collision with Stoke's Marko Arnautovic and looked to have dislocated his shoulder.
Mathieu Debuchy returned to action mid-week in his familiar right back spot but with Calum Chambers suspended and Laurent Koscielny injured he may well play his first Premier League match in months at center back.
Good news for Arsenal fans, Mathieu Debuchy has a bad ankle sprain and doesn't have any broken bones.
Another long-rumored transfer came to it's inevitable conclusion today as Mathieu Debuchy was officially announced as an Arsenal player.
Daryl Janmaat's agent has tweeted that his client's move to Newcastle United will be completed tomorrow for a very reasonable €6 million.
Reports across Europe indicate that Arsenal are at the finish line with the signings of Mathieu Debuchy and Alexis Sanchez from Newcastle and Barcelona respectively.
Rumors this morning have Arsenal getting tantalizingly close to signing two players and shifting their attention to a third as they look to upgrade their squad in key positions.