It's a risk our club are taking for the benefit of the club.
That's what you implied when saying you hope he can repay the club. That suggests he's indebted to us.
He has nothing to repay. Firstly, he's helped get us promoted. And the new contract offer isn't the club doing him a favour, we're protecting our investment too, he's worth a good chunk on money.
GM had a poor match, that's all. He doesn't look fully fit, and had an off day. As Westander says, he's similar to Hemed and Murray anyway, we either want different options or a big improvement on the those two, and I don't think Ulloa is much better.