FOXBORO — The short answer is they don’t know.

Joe Burrow might return Sunday in an attempt to begin saving what’s left of the Bengals season when the Patriots visit for a 1 p.m. kickoff. Or Cincinnati could turn again to 40-year-old Joe Flacco, who’s started the Bengals’ last five games while Burrow recovers from a turf toe injury.

Either way, the Pats know they won’t learn which quarterback they’ll face until Cincinnati makes an official announcement.

So in the meantime, they will continue keep busy by preparing for both quarterbacks.

“It’s more about things we can control. We can’t control that,” Patriots safety Jaylinn Hawkins said Thursday. “We’ve got to control what we can and stay locked in, stay poised and ready.”

As a spot starter, Flacco is 1-4 with a 63.4% completion percentage, 12 touchdowns and three interceptions. He’s sustained the deep passing element of Cincinnati’s offense in Burrow’s absence, though the Bengals will take a hit Sunday without star wide receiver Ja’Marr Chase who’s been suspended one game for spitting on Steelers safety Jalen Ramsey last week. If Flacco plays, the Patriots understand the importance of applying pressure on Flacco, whose performance under duress has been dramatically worse than when he’s afforded a clean pocket.

“You’re not going to trick him,” Pats coach Mike Vrabel said this week. “You’re going to have to cover him, beat him, rush him. The ball comes out quick. (He) doesn’t seem to get rattled very easily. It’s not something that’s going to happen.”

Burrow, a top-5 quarterback when healthy, also prefers to play from the pocket. He’s long ranked among the most accurate passers and fastest processors in the league. It’s unclear how much rust Burrow will have if he does play Sunday, four days before his reported target date of returning on Thanksgiving night when the Bengals will play at Baltimore.

Before he was injured in Week 2, Burrow went 21-of-36 for 189 yards, two touchdowns and zero interceptions in Cincinnati’s first two games. But whether it’s a rusty Burrow or an aging Flacco, the Patriots aren’t taking either lightly while they run out the clock until kickoff.

“Flacco’s been around for a long time, so he has a lot of experience. And (Burrow) plays at a high level,” Hawkins said. “They both have different parts of their games that make them great.”