Selling Laca would mean having to rely on Welbeck as the second striker which is a disaster waiting to happen should Auba miss games due to injury.
Emery would be risking his job with such an idiotic move. We would struggle to score goals and accumulate losses.
Laca is the perfect striker playing behind Auba because Laca is not just a striker. He can play the wings, be involved in the build up, and support Auba.
We would be stupid to let him go.
He was just fine for his first season in a new league, given Wenger's absuridity in handling his playing time.