When is a player too old to develop?

A few years into my current save I managed to get Jack Wilshere from Arsenal for £2m. He was 141 CA with 170 PA, but only 26 so I figured I could still take him quite high, if not to 170. However I've been unable to increase his CA and he's now at 140. Is 26 too old to increase CA?

A players development will slow after a certain age, but it won't stop unless he doesn't train very well or his training plan isn't set right.

Wilshere will need high levels of professionalism and ambition to train properly, and how are you training him?

I'd guess that injuries have stunted his progression over the years too though

Yes, that's Wilshere's big problem both in FM and in real life. Too many lenghty (and numerous short) injury periods means he will probably never reach his full potential. As a Arsenal manager, I know the issue well. He's on the wage of a regular first-teamer, but his lack of progress means that he remains 3rd or 4th choice as a central midfielder - when he's fit. And he's not easy to sell, so whenever another club offers a reasonable fee for him, I have to seriously consider it. That being said - when he is fit, he's a very good footballer, even if his CA is 20 or 30 points below his PA. A regular first-teamer for most clubs, just not the very top ones. You know ... the ones that has Pogba, or Kroos, etc. Or in my case, a midfield trio of William Carvalho, Ramsey and Özil, with Coquelin and Cazorla as alternatives ... where's Wilshere's first team spot in that mix? Only when the other alternatives are not available, for some reason.

But if you have not already filled your midfield with world class, and you can get Wilshere for 2 million .... that's a bargain. You get nearly world class for very little money.

It depends on several things

1)Training Facilities and your training

2)Player's personality( professionalism and ambition as the mod mentioned above)

3)Injury

4)Playing Time

5)Division that your team playing in.

6)Age

Players over 23 can hardly have big boost on physical attributes.

Young Players can boost 10-15 CAs in 1 year if he is professional and get enough chances.

So for Jack, IMO he can never reach max PA but still has chances to reach 160.