Whatever you do, don't forget to give him some breaks, even through assigning him as a sub here and there. "Inept" game shape really hurts his performance.
Moneywise, 40k salary for 100k DMI is a waste of your money. My 24k forward does have 240k DMI because his "proficient" GS, and I pay just 7-10k to 70-80k DMI players. Thus, you really have to control weekly minutes better.