The time that your player will stay on the floor, depends on various things.
- The strength difference between the starter and the subsitute
- The game score, if > 20, the coach will put the subsitute on the floor, however if your are loosing he might keep your starters for 40 or more minutes.
- The subsitution mode you choose.
To get around 24 min, I usually start my usual Subsitute, and put my stronger player in second place on the depth chart. And choose Coach pick from depth chart.
However not knowing the relative strength of your starters vs Substitutes I cannot guarante the result. You should practice it for yourself to get a feeling of the result.
Be careful with Let coach decide as with this option, the coach can put a player at a different position than the one you indicated. He can even put a player you didn't put at any position, on the floor.
So if you don't want a player to have any minutes, be sure to remove him from the team roster.