Unfortunately, recovery times for strains are unclear and there is no standard return to play expectation. Strains are at the forefront of recurrent to more severe, even cascade, injuries; frustratingly, the highest risk of re-injury is within the first few days after returning to play. The severity is measured in grades: Grade 1 muscle strains recovery expectation is zero to two weeks, Grade 2 two to six weeks, and Grade 3 four to eight weeks or longer. As rule of thumb, be wary of players who return at the most optimistic end of the recovery timetable.

Knee injuries: These prevent athletes from bending or stretching their knees properly. Quick, sudden direction shifts while running and direct blows to the knee are the most common cause.

These injuries impact on the cartilage and the ligaments that hold the knee together, so on the mildest end of the board, you’re going to see things like jumper’s’ knee (6 weeks), which is caused by repetitive strain to the knee resulting in pain, and tears to the meniscus. The meniscus is a shock absorber and helps prevent injury to the knee. If fragments of the meniscus are removed, you’re going to see players come back to play fairly quickly, 1 to 2 weeks. But if surgery is needed to repair, think more along the range of six weeks and longer.

 
Medial collateral ligament (MCL) sprains on the milder end (Grade I) may allow a player to play with a brace and not miss time at all. Generally, no surgery is needed to heal, even with Grade III tears, although some extreme tears may require surgical reconstruction of the area. 6 weeks is the standard here. 

Season-enders include patellar tendon tears, that is, the tendon between the kneecap and the shin, and anterior and posterior cruciate ligament (ACL & PCL) sprains or, even worse, full tears. These injuries often occur after a sudden cut or pivot move, and may require anywhere from 6 to 18 months to heal properly and absolutely, with surgery and extensive recovery times. 

Ankle sprains: These are also extremely common injuries in football. High ankle sprains heal more slowly than low ankle sprains, something to take into account. The mildest forms will have no downtime after aggressive rehabilitation. Grade I will need typically 1 to 2 weeks; Grade II, 3 to 4 weeks. Grade III, 6 to 10 weeks. 

Fractured bones: They almost always require surgical fixation to heal properly. Long bone fractures in arms and legs normally take 4 to 8 weeks. Broken hands, thumbs or fingers really depend more on the duties of the position: linemen or linebackers may return to play sooner than wide receivers or running backs. Rib fractures take 6 weeks. 

Now, in the unlikely and unfortunate case of YOU getting injured during fantasy football season —namely, you know, throwing ball, goofing around, or even just undue strain because you were reaching out for the Tostitos that go with the guac—, remember: the most appropriate course of action for musculoskeletal injuries, that is, bone injury, pulled or sprained muscles or joints, is RICE. 

It stands for Rest, Ice, Compression, Elevate. And it goes like this: rest the injured area for 48 hours; ice for 20 minutes at a time four to eight times a day; compress to help reduce swelling; elevate the injured limb 6 to 10 inches above the heart.

Enjoy the season!
 
Sources:
https://subscribers.footballguys.com/apps/article.php?article=16bramel_navigating_injuries
https://reverehealth.com/live-better/10-common-football-injuries/
https://www.ncaa.org/sites/default/files/NCAA_Football_Injury_WEB.pdf
https://www.4for4.com/fantasy-football/nfl-injuries-defining-look-0
https://www.verywellhealth.com/what-is-rice-190446