As it currently stands, the availability of the Patriots' quarterbacks are all very much in question. Tom Brady is suspended for one more week. Jimmy Garoppolo is coming back from an AC joint sprain (timetable unclear). Jacoby Brissett reportedly sustained a thumb injury on his throwing hand during last week's game (though it looks like it doesn't require surgery).
This combination of factors has lead to the reasonable conclusion that the Patriots would likely be in the market for the services of a fill-in quarterback if either (or both) non-suspended QBs aren't able to play Sunday.
At least for the time being, it seems that the team is confident that either Garoppolo or Brissett is in good enough shape to take the job in Week 4. At 3-0, there probably isn't a lot of reason for the Pats to panic and make a big move. The story said Yates would be a leading candidate.