SANTA CLARA -- If the 49ers had decided against any possibility of playing Jimmy Garoppolo on Sunday, the club would have added a third quarterback to its 53-man roster.

But the 49ers’ depth chart heading into Sunday’s game against the Arizona Cardinals consists of rookie starter C.J. Beathard and Garoppolo. That's it.

That means, if something were to happen and the 49ers needed a replacement for Beathard, Garoppolo would get the call to play -- just five days after landing in the Bay Area courtesy of the trade with the New England Patriots for a 2018 second-round draft pick. Coach Kyle Shanahan said Garoppolo will be active and in uniform for Sunday’s game at Levi’s Stadium.

Shanahan shed more light on the 49ers’ quarterback situation during an interview for “49ers Game Plan,” which airs Saturday at 7:30 p.m. on NBC Bay Area (Ch. 3).

Here is what Shanahan had to say about his first impressions of Garoppolo and when he will know it’s time to make him the 49ers’ starter:

On first impressions of Garoppolo:

“Really what I expected. I spent a lot of time with Jimmy when he was coming out of college. I went down there and worked him out a bunch. He’s a very good thrower. I haven’t seen him in person really since then. And to see him out there the first day of individual (portion of practice) throwing routes to the receivers, the ball comes off his hand. He can spin it well. He can drive the ball. I think you can see why he was a highly touted guy around this league. Just being around the guy these last few days, he’s a real good person. The way he comes off on TV to everyone, that’s the way he is all the time. He’s a very likeable guy that teammates like. He’s someone we’re going to enjoy having him around here. We enjoy his talent, also. I'm looking forward to working with him.”

On the process of getting Garoppolo ready to play?

“It’s tough. It’s a challenge. It’s a challenge for the whole team, and it’s a huge challenge on him. Jimmy has gone about it as hard as he can. He’s put the work in. But I don’t care who you are or how many hours you put in, there’s no way you can get it all down in that short amount of time. If he does get the opportunity to go in, you got to scale it down. You have to wristband a bunch of stuff. You got to be very selective in what you call and make sure he understands what you’re doing. It’s not just the pass plays. It’s the snap count, the cadence, how to get out of the huddle, where the run plays are going, the ball-handling and all the little things that people take for granted that take a lot of time to work on. We’ve got in enough this week so that we know we can survive to a degree if he had to come in. But, hopefully, we can keep C.J. healthy through this game.”

On the difference of Patriots and 49ers terminology:

“Their formations are numbers. And we might say, ‘Wide right clamp, F right out, three jet, Y stucko, F choice.’ There are different things we say, and they use more numbers. It’s what does ‘wide right’ mean? What does ‘clamp’ mean? What does ‘F short’ mean? What does ‘stucko’ mean? What does ‘choice’ mean? There’s about 40 different things that those words mean. One’s a route, but it tells the guy next to him to do something. One’s a protection. One’s a formation. That’s why we work at this year-round. That’s why it’s so important to have OTAs and things like that for these players. Jimmy’s been in this league a little bit. You’d think that would help. But it is different when you go to a new team. That’s why it’s going to be a work in progress. I don’t know how long it’s going to take, but I know we got a very good player here, a very good person, and someone we’re very excited to have.”

On excitement Garoppolo trade brought to team:

“Yeah, I think it excites guys. When players see that on Monday and they come in on Wednesday, you can feel a little different buzz. I think we had a great week of practice. I think C.J. had his best week of practice. On Wednesday, we only had two balls hit the ground. We haven’t done that all year. So I think it did give us a little bit of juice and some energy. Jimmy has fit in really well in that quarterback room. He’s fit in real well with the guys, and I think the guys see the talent out there, also. I don’t think anyone’s trying to rush it or knows when it’s going to happen, but people can see we have a few good quarterbacks in our building.”

On when he will know the time is right:

“That’s something I’m going to take day-by-day. It’s not just about Jimmy. It’s about our team, too. I want to make sure I put Jimmy in a position where I believe he has a chance to be successful. That’s a huge challenge for a guy when he’s hopping into the middle of this year. We’re not the healthiest right now. That’s not all that's going into the decision. I got to wait until Jimmy’s ready. And I got to wait until I think when he goes in, he has a chance to successful. If that time comes or when it comes, then we won’t hesitate to do that.”