Just 10 days ago, the suggestion would have called for an immediate blood-alcohol test.

But it’s true: The Buffalo Bills are planning to start Week One against the mighty New England Patriots with undrafted free agent Jeff Tuel as their quarterback.

Coach Doug Marrone made that announcement Monday as part of a dizzying day of developments at One Bills Drive.

“I don’t know if I’d use the word crazy, but I would say a little bit of adversity, for sure,” Marrone said of his quarterback depth chart. “Right now, we’re planning on Jeff Tuel playing the first game.”

The Bills find themselves in this situation after rookie first-round draft pick EJ Manuel had minor knee surgery last week and veteran Kevin Kolb suffered a concussion Saturday in the preseason game at Washington.

That necessitated the team’s acquisition Sunday of veteran Matt Leinart via free agency and Thaddeus Lewis via a trade with Detroit. They participated in their first practice with the Bills on Monday and are expected to make their debut in Buffalo uniforms Thursday in the preseason finale against the Lions at Ralph Wilson Stadium.

Marrone has not ruled Manuel out for Opening Day, saying he will evaluate him once he returns to practice. But in the meantime, Tuel will run the first-team offense, as he did during Monday’s practice.

“I came here to play football, and that’s what I’m doing. Anybody that comes to a team thinking, ‘I want to come here and just sit on the bench,’ is wrong,” said Tuel, an undrafted rookie free agent out of Washington State. Tuel said his biggest challenge in getting ready for the Patriots will be earning the trust of the team’s starting receivers.

“I haven’t thrown many balls to Stevie Johnson or T.J. Graham or guys like that,” he said. “It’s kind of scripted so Kevin and EJ were throwing with those guys and I was throwing to the twos and threes. So just getting used to how they run routes and certain timing routes is going to be the biggest challenge, to be able to put the ball where I need to be able put it.

“Like today a couple times, I found myself a little late to Stevie because he does things a little differently and quicker. That’s going to be the biggest challenge for me, getting to know my guys and getting on the same page with them.”

Tuel has done what’s been asked of him in the preseason. He’s completed 31 of 43 passes for 299 yards with two touchdowns and zero interceptions for a passer rating of 106.6, third best in the NFL during the exhibition season.

“It’s crazy. He was undrafted and now all of a sudden he has potential to start Week One against New England,” Leinart said. “From what I’ve seen and I’ve been reading, prior to even signing, is he’s a talented player and a smart kid. As long as I’m here, I know I’ll help him out and at the same time compete. I told him, ‘Hey, in this league anything can happen. You always have to stay ready.’ “

As a freshman in 2009 with the Cougars, Tuel’s first game came against Southern California in the Coliseum.

“It’s happened to me before,” he said. “I came here and prepared like I was the starter since Day One. It can happen.”

It will, provided Manuel is not ready in time.

He went through an on-field workout with trainers Sunday, one week after having the procedure done on his left knee.

The outlook for Kolb, meanwhile, is grimmer. The veteran suffered his third confirmed concussion in the last four seasons, leading Marrone to say he’ll be out of the lineup “for some time.”

With the final 53-man roster needing to be set by Saturday, the Bills have less than a week to determine Kolb’s future with the team. Marrone did not rule out any option, including placing him on either season-ending injured reserve or the injured reserve-designated to return roster spot.

“With a concussion … it’s a tough situation,” the coach said. “There’s this large protocol, which I schooled myself on last night, trying to understand it, that they go through and I think as they go through it, there’s no predictability as with a normal injury to see where they’re at.”

Marrone said he spoke with Kolb on Monday morning, and the quarterback is not thinking about retirement at the moment.

“He’s not even in that thought process right now,” the coach said. “Right now he’s in the thought process of really clearing up and going through the process of clearing up the concussion.”

Marrone, though, did not rule out the possibility that Kolb’s playing career could be over.

“I think that we all understand the issues of concussions and we all understand the issues of multiple concussions. These things can be part of the thought process at the right time,” he said. “I’ve been involved with it at the collegiate level where players had multiple ones and he has stopped playing. But that comes I think when, OK, where are we at, what’s going on, and that’s a lot of personal discussions that go within the player and his family and the agent.

“So I’m not saying that that’s not a possibility. I think with a lot of injuries it is because this is a very tough game that we play. Can I foresee that being the case and that being discussed? I can’t answer that question and that’s what I asked Kevin about this morning. You know, right now he’s concentrating on going to the protocol, getting better and then seeing what’s going on because there is a lot of emotion …so I think he’s just trying to get everything straight.”