There’s no said age that one can’t play on past, but the mid-30s is generally when most players have either already retired or at least considered it. Of course, you have your Jimmy Andersons who defy age expertly, but judging by their interviews, I doubt Khawaja and Warner will still be playing Test cricket in five years.
Khawaja has said he considered his career over for a brief moment between his last stint for Australia and his current one, and Warner specifically citing goals for next year say that he wants to keep going, but doesn’t see himself remaining for too long. If they do somehow manage to press on for years coming, that would be bad news for the current crop of Sheffield Shield openers.
When will Warner and Khawaja call time, and why does that matter?