Sprains (ligaments) strains (muscles) are determined by grades for injury's. .
1- minor, only a few fibres are over stretched. 1-2 weeks
2- medium, larger percentage of fibres are stretched and some are ruptured. 4-6 weeks
3- major, complete tear of the muscle or ligament and usually requires surgery. 8-12 weeks
Ross will have a significant grade 2. He wouldn't be moving like he was with a grade 3. Wouldn't haven't been in the stands.
One of the quads though, tough one to rehab as it's explosive in the concentric and eccentric phases of movement and striking a ball. One to one definitely and could easily take longer than 8 weeks to get back to 100%.
It's a ****ter.