Sometimes, Arsene Wenger had an excuse for running his players into the ground last season: There was simply no one to replace them. But often the manager would simply stick to a line-up he trusted.
There needs to be more tactical shifting based on other teams' strengths and players' fitness next season. Olivier Giroud is unable to perform at his potential when he is forced to carry the attack for nearly every minute of every game, and Aaron Ramsey's prolonged injury layoff was likely due to the fact that he played almost every available minute during the first half of the season.
Hopefully, Arsenal can add more players than they let leave this summer to help alleviate that problem. Though Mathieu Debuchy would merely be a replacement for Bacary Sagna, Alexis Sanchez would be a proactive addition.
Another centre-back is probably needed, but as long as Wenger can rest his best players routinely, the squad will be able to perform at the level it is capable of.