In an alien world, due to changes in the ecosystem animals that were once mostly arboreal started having to spend more time in open plains, adapting to fill a new niche of grasslands/bush eaters and predators. The predator in question evolved from a creature with long, four- fingered limbs, employing knuckle walking on the ground to conserve its claws, which it used for climbing and taking down prey.
In this scenario, could a previously arboreal predator maintain its knuckle walking while becoming a predominantly cursorial predator? What changes would their front limbs suffer to allow this?
Additional information: The creature is roughly the size of a small spotted hyena and was originally a quadrupedal digitigrade, with limbs ending in structures similar to zygodactyl birds (2 opposable digits, slightly smaller than the two middle digits, with the middle ones being used for knuckle walking). Its prey was also originally adapted for arboreal life, and there were no other predators of prey already filling the new niches. In the new environment there are still trees, which it will climb for resting, like some modern day big cats. Its neck has 15 vertebrae and is flexible like an owl's, previously used to search for prey along with its sharp vision. The mandibles aren't used in active prey takedown. Its overall skeletal structure is similar to our world's due to coming from an similarly structured ancestor (yes, I know how unlikely that would be).