Everything was going quite well for the New England Patriots on Sunday, with backup quarterback Jimmy Garoppolo dealing, throwing a trio of early touchdowns against the Dolphins. The Pats looked a team with some real depth at the position.

And then Garoppolo went down with a shoulder injury. And now it could cost him as much as six weeks.

CBS Sports NFL Insider Jason La Canfora reports tests are still being done on Garoppolo's shoulder, while Jeff Howe of the Boston Herald hears the same thing but adds the team does not expect to have Garoppolo ready for next week against Houston.

Additionally, Howe believes the team is expecting the backup to miss up to six weeks with the injury.

Dr. Mark Adickes, who does work with sports media companies as an injury analyst, believes it's unlikely Garoppolo would return before Tom Brady comes back from suspension.

"If it's a Grade 1 sprain, these ligaments are only sprained. That's the kind of injury you can come back even in the same game or a week or two. In a Grade 2 sprain, you tear these ligaments and sprain these ligaments. That's the kind of injury you see someone out four to six weeks," Adickes saidin a television interview on the NFL RedZone. "With a Grade 3 sprain, you tear these ligaments, you tear these ligaments, the clavicle is way up. That requires surgery for someone to come back, so that would end his season.

"Given the way he went down on that shoulder, I think it is unlikely that he plays prior to Tom Brady returning."

That means either the Pats acquire a quarterback or simply roll with rookie quarterback Jacoby Brissett. Brissett, drafted in the fourth round out of NC State, entered the game after Garoppolo's injury and went 6-for-9 for 92 yards, helping the Pats drive down for a touchdown.

Brissett drew praise from both Bill Belichick and Julian Edelman.

Despite the optimism, it would be a first for Belichick to start a rookie quarterback in New England, according to the NFL's research department. The last Patriots rookie to start was Drew Bledsoe, who got Wally Pipped by Brady in 2001.

The good news for the Patriots is they're currently 2-0 and reinforcements are coming back in three weeks.