Here's the stats for the average age of the premier league squads, in a weird order. I nicked it from transfermarkt.
Manchester City 27,7
CHelsea 28,3
Manchester United 27,4
Arsenal FC 26,5
Liverpool 26,1
Tottenham 26,4
Everotn 27,1
Newcastle 26,4
Swansea 26,8
Southampton 26,1
West Ham 28,1
Sunderland 26,6
Aston Villa 24,7
Stoke 27,8
Fulham, 28,2
West Brom 28,5
Cardiff 26,1
Crystal Palace 28,1
Hull City 28,3
Although average age is a very rough estimate and doesn't single out the most important players' ages compared to the less important, I'm surprised by three things
1. Manchester United's squad is on average younger than than ours, not older. Not by much but still.
2. Arsenal's squad is not that young. In fact, of the top teams Newcastle, Tottenham and Liverpool out-age them. Or whatever you call it. Again, not by much but still. Considering Arsenal has this myth of producing youngsters on a regular basis you expect them to be further up than seventh in the league.
3. Aston Villa have by far the youngest squad, which makes me like them even more as underdogs. Oneill's Aston Villa always seemed so old (although I don't know if that was an impression matched by fact).
We have the twelth youngest squad, which is not necessarily bad but not good either. We were buying them young or youngish but of the players that came in this summer, only one wasn't 28 and that was Jovetic.
Cause for concern or nothing to worry about? For me, it's all about what the transfer window this summer brings and how many youngesters get the chance for sub apperances next season.