I think its because your guys are now 27 and above so your coach is trying to avoid exhaustion. Don't worry about it. Your guy will get full training with 40 minutes since they are 27+
This is from the game manual
Training Minutes
How many weekly minutes each age group need for full training?
18-19 years old: 45 weekly minutes.
20-26 years old: 48 weekly minutes.
27+ years old: 40 weekly minutes.
Note: One minute buffer is placed for all age groups, which means 44 minutes is also sufficient for 18-19 age group.