There is a lot of misinformation about squad rotation and Arsenal. First of all, contrary to the beliefs of some, squad rotation is vitally important. Among the teams with the highest wage bill, it was not the team with the highest wages, but the team that had the most players playing ten games that won the Premier League. Also, contrary to popular belief, Arsenal actually do have quite a bit of squad rotation (though arguably this is rotation forced upon the team by injury). A quick look at a few summary statistics suggests that the best thing for Arsenal to do in order to improve its chances of winning the EPL is to improve on the quality of players 12-18.
The following are some statistics on squad rotation for outfield players for the Champions League clubs.
Players with 30+ starts: 6 (RVP, Carrick, Evera, Rafael, Ferdiand, Rooney)
Tenth outfield player: Danny Wellbeck (23 starts)
Players making 10+ starts: 21
Players with 30+ starts: 10 (Toure, Tevez, Zabaleta, Silva, Barry, Kompay, Clichy, Nasri, Natasic, Aguero)
Tenth outfield player: Sergio Aguero (30 starts)
Players making 10+ starts: 16
Players with 30+ starts: 11 (Ivanovic, Luiz, Ramires, Mata, Hazard, Torres, Cole, Cahill, Azpilicueta, Oscar, Lampard, John Mikel Obi)
Tenth outfield player: Frank Lampard (42 starts)
Players making 10+ starts: 15
Players with 30+ starts: 8 (Cazorla, Arteta, Mertesacker, Vermaelen, Podolski, Giroud, Sagna Walcott)
Tenth outfield player: Gibbs/Koscielny (29 starts)
Players making 10+ starts: 19
First of all, the importance of squad rotation in Manchester United's success should not be understated. While they may have had few truly elite players beyond Rooney and a foul odor emerging from Holland, it certainly helped to have players with the quality of Shinji Kagawa (22 starts, 13th among outfield players), Ashley Young and Ryan Giggs (both 18 starts, tied for 15th) to spell the first eleven starters. By comparison, Arsenal gave 21 starts to a raw Carl Jenkinson and 18 to Gervinho. Aaron Ramsey, 11th with 28 starts, was the best of the bunch outside of the top 10 in starts, and he hardly has the quality of Shinji Kagawa.
Ultimately, if Arsenal are going to improve on their previous league finishes, they need to get players of better quality backing up their top players. Additionally, if Arsenal can improve the quality of their starting XI by getting players like Luis Suarez, we should not be concerned about what it will mean a player forced out of the fist XI. While they may no longer be first choice, their contribution will still be essential if Arsenal are going to lift a trophy at the end of the year. Youth prospects that are not of the necessary quality can get the odd game or go out on loan, but what this argument suggests is that Arsenal would be best served by making players like Serge Gnabry and Gidieon Zelalem earn their way into playing time instead of getting it handed to them by lack of depth or an unwillingness to make signings.