SANTA CLARA – Eric Reid spoke to Bay Area reporters Tuesday after practice. Here’s what he said.

Q: How complex is the 49ers’ defense?

REID: It’s more complex than college, but it’s something I think I can handle. It’s a challenge, but it’s something I like to challenge myself with. I’ve got to study my plays every night. Every day is a new day and I’ve got to come out and prove myself.

Q: What’s the biggest adjustment for you right now, the speed of the game or the size of the playbook?

REID: I think I’ve adjusted pretty well to the speed. Everybody’s fast, from the D-Line all the way to the top of the roster. For me, it’s just knowing my plays. The playbook is way bigger than in college. On a different play, I’m doing something completely different from the last [play], so it’s just more mental than it was in college.

Q: Is there more on your plate when Donte Whitner isn’t out there?

REID: A little bit. They expect me to make more calls. That goes back to studying my plays every day. And that’s realistic, because in this game somebody could get hurt and you never know when it happens. If he’s not in, then it’s my turn to step up and make some calls.

Q: And how’d you do out there today?

REID: I think I did pretty well. I can always do better. There were a couple of calls I was kind of confused on – shaky – but we just installed them yesterday. I’m going to get back in my playbook tonight and get it fixed for tomorrow.

Q: Did you make most of the calls in college?

REID: Yeah, me and Kevin Minter, the middle linebacker. That was part of my responsibility, and same here except not as much because we’ve got a couple of good linebackers handling those calls.

Q: Do you they have you primarily playing free safety or are they trying to get you familiar with both?

REID: Technically, I’m at free, but depending on motion or the change in strength of the offense, your responsibility could change to strong, so you have to know both positions.

Q: It seemed like you, C.J. Spillman and Craig Dahl got equal time at safety with the No.1 defense today.

REID: Yeah, we were just rotating – three plays and then we switch spots. Like I said, you have to know both safety spots. We got good reps today.

Q: Is that how it’s gone for you most of the time in OTAs – rotating in with the first team?

REID: Yeah, and when I’m not in, I’m getting mental reps. Every play, I envision myself as being in on that play. No play goes wasted.

Q: Have you had that moment where you did something completely wrong on the field?

REID: Oh yeah, definitely. Every day we’re installing new plays, so sometimes it’s hard to remember something new and fresh and have to do it perfectly on the field. There have been a couple of times where I was like, “Man, I was wrong on that one,” but Coach comes up to me and tells me what I’ve got to do to fix it, and you’ve got to do it right the next time.

Q: What’s tougher, the SEC or the NFL?

REID: (Laughs) The NFL. It goes back to the speed and the mental aspect. If you’re half-stepping, Vernon Davis is running by you from the tight end, or the X receiver is running by you, and if you don’t know what you’re doing, you’re going to mess up the guy next to you. You’ve got to be on your toes at all times.