The NFL has experienced a rash of injuries in the early part of the season. Key players on some of the league’s best teams are hurt in Week 3, and a couple might not see the field again in 2016.

The Minnesota Vikings received the biggest blow in Week 2 when they defeated the Green Bay Packers. Not only has left tackle Matt Kalil been placed on injured reserve, but Adrian Peterson suffered a torn meniscus in last Sunday night’s game that will reportedly keep him out for three to four months.

The team was hopeful that Peterson might only miss a few games, but it appears their star running back could be done for the year.

“When you repair a meniscus, you’re looking at six weeks of very limited rehab while you’re waiting for it to heal,” Dr. Mark Adickes, chief of sports medicine at Baylor College and medical expert for ESPN & DirecTV's Fantasy Zone, told International Business Times. “You’re looking at another six weeks of controlled rehab before you allow someone to really go full out to get into football shape, so that’s why they’re saying three to four months or perhaps the entire season.”

According to Adickes, Peterson could have avoided surgery by removing the meniscus instead of repairing it, but that would’ve led to a very arthritic knee later in life for the running back, eventually requiring a joint replacement.

The Vikings have won their first two games without much help from Peterson. He’s totaled just 50 yards on 31 attempts, and his 1.6 yards per carry are the lowest through the first two games of the season since the 1970 NFL-AFL merger.

But Minnesota might feel Peterson’s absence in the coming weeks. Just the threat of the running back making a big play keeps opposing defenses on their toes. He led the league in rushing a year ago and won the league MVP award in 2012 with 2,097 yards on the ground. The Vikings face a tough upcoming schedule with games against the Carolina Panthers, New York Giants and Houston Texans.

Minnesota will rely on one of the NFL’s best defenses, having lost starting quarterback Teddy Bridgewater for the season with a leg injury in the preseason. The New England Patriots are already down two quarterbacks, but it hasn’t stopped them from looking like the Super Bowl favorites.

Jimmy Garoppolo Patriots Jimmy Garoppolo might not play again this season after getting hurt against the Miami Dolphins on Sept. 18, 2016 at Gillette Stadium in Foxborough, Massachusetts. Photo: Getty

Jacoby Brissett started at quarterback on Thursday night in New England’s 27-0 rout of the Houston Texans, in place of the suspended Tom Brady and the injured Jimmy Garoppolo. Garoppolo had been pegged as the starter until Brady is allowed to return in Week 5, but he suffered a Grade 2 AC joint sprain in the team’s Week 2 win over the Miami Dolphins.

Considering the way New England has played in the first three games, they could seemingly win with anyone at quarterback against the Buffalo Bills in Week 4. But having Garoppolo under center over Brissett would certainly be ideal. Garoppolo was performing like an All-Pro before he got hurt, and Brissett only threw for 103 yards on Thursday. With Garoppolo injured, wide receiver Julian Edelman is the team's backup quarterback.

New England hasn’t ruled out a return for Garoppolo, but it looks like he’ll be sidelined until Brady’s suspension is up. Even when Garoppolo gets healthy, he might not take another snap with Brady back in the fold.

“I’ve had that injury, and it took me three weeks to be able to do a pushup,” said Adickes, who played six years as an NFL offensive lineman before making a career change. “I would think throwing a ball at NFL quarterback-caliber would take at least the same amount of healing that it would take me to do a pushup...Most people would say a Grade 2 AC (sprain) is a four-to-six week injury.”

Other notable injuries include Chicago Bears quarterback Jay Cutler, who is expected to miss two to three weeks with a thumb injury, though surgery could keep him out longer. A hamstring injury could force Tampa Bay Buccaneers running back Doug Martin to miss three weeks, and Denver Broncos linebacker DeMarcus Ware might miss a month after having surgery on his forearm.