RICHMOND, Va. -- For the first time in a long time, there is a quarterback controversy brewing in New England.

No, Tom Brady isn't near being pushed out to pasture after celebrating his 37th birthday last week. In fact, he looked as dominant as ever in joint practices this week with the Washington Redskins.

Brady and many of the Patriots' key players were given the night off in the preseason opener on Thursday at Washington, a 23-6 loss to the Redskins.

But Brady's time on the sideline gave extra reps to fourth-year backup Ryan Mallett, who started the game, and rookie second-round pick Jimmy Garoppolo.

After the game, the questions were not about Brady but about his backups. Mallett struggled in first half against the Redskins and Garoppolo was impressive in the second half in his NFL debut.

Mallett, who has thrown just four passes in the regular season since being drafted in the third round in 2011, completed just 5 of 12 against Washington for 55 yards and a 55.9 passer rating. He had trouble with accuracy and decisiveness, and a mixture of starters and backups on the offensive line didn't make his job any easier.

"There was good, there was bad," Mallett said. "I felt comfortable back there. I did a few positive things. A few things I'd like to do different, but that's what practice is for."

Garoppolo completed 9 of 13 passes for 157 yards and a touchdown with a 135.7 passer rating. He put together the Patriots' only scoring drive of the night, had an apparent touchdown pass called incomplete on a deep ball and saw a fumble negate another drive.

For a guy who has struggled quite a bit on the practice field in the last few weeks, Garoppolo looked the part of a comfortable NFL passer.

"I did all right," Garoppolo said. "There is a lot of stuff to improve on. It's a process. For any rookie quarterback, there's a lot to learn. We'll go watch tape and go fix those things."

Shortly after the loss, Belichick emphasized that the team "has a lot of work to do." During a Friday conference call with the media, Belichick was only a tad more complimentary of his developing young backup.

"When you look at the overall opportunities that Jimmy's had from the beginning of OTAs through training camp, it's in the high 20s somewhere -- the number of practice days. Just because a player makes a mistake doesn't mean they're always going to be there," Belichick said of Garoppolo's difficulties in practice. "You'd like to think that some of them will be corrected, and the next time the situations occur, the reactions are executionally better.

"I think we see that with pretty much every young player, including him. I think there were some things he did well last night, some other things he learned from."

The learning process is something that Mallett has been going through for nearly four years. Garoppolo is at a much earlier point in that process and showed some flashes of competency in his first game action.