49ers training camp, Day 4: The Brandon Aiyuk show

Whether it was Trey Lance or Sam Darnold under center, Aiyuk was targeted early and often during Sunday’s practice.

The 49ers returned to practice Sunday in what was their final practice without pads on. Knowing Monday was bound to be physical and full of energy, a couple of starters had the day off.

Christian McCaffrey had his cleats on and was in line for individual drills, but was without a helmet and didn’t participate in anything. McCaffrey got plenty of work in after practice, however:

McCaffrey has been on a maintenance plan dating pack to OTAs and the spring, as the 49ers will monitor McCaffrey and ensure to keep him healthy for the duration of the season.

Unlike McCaffrey, star left tackle Trent Williams wasn’t at the Niners facilities Sunday. Jaylon Moore filled in with the first team at left tackle in Williams’s absence.

Sunday was also a scheduled day off for Brock Purdy, who was running on the far field pre-practice while the team was stretching. Kyle Shanahan said after practice that Purdy’s throwing schedule remains the same. He’ll have two practices on and one off. But he clarified that Brock will also have two days on then two days off.

Since the team was off Saturday, Brock should return Monday.

The battle behind Brock

Purdy sidelined meant Trey Lance, Sam Darnold, and Brandon Allen would duke it out for the backup quarterback spot. The reps were fairly even during each team period. Trey Lance received 12 first-team reps compared to Darnold’s four, but Brandon Aiyuk, George Kittle, and Deebo Samuel all worked with the first and second teams.

Lance had 16 reps in total. He started each team drill but one. During the first session, Lance completed all three of his attempts, including a 30+ yard pass to Kittle, who was streaking down the sideline. The pass was placed to perfection in between the cornerback and safety.

Perhaps just as importantly, Lance drew Arik Armstead offsides on the drive, which gave the offense a free five yards. Practice consists of more than completion percentage, as that rarely, if ever, tells the whole story for quarterbacks.

For example, during the second team period, Lance called an audible away from a blitz and checked into a run in the other direction. Good. Unfortunately, there was a fumbled exchange between him and center Jake Brendel. Bad.

The red zone periods are the most entertaining portions of practice, as that’s where all the action happens. On Lance’s first dropback, the high-low concept called for him to go to the left side. But the defense sniffed it out and took both routes away. Lance didn’t force a mistake and made it to his third progression, which was a running back on the other side of the field.

All of this happened in rhythm and led to the offense staying on the field. Lance would finish the series with a completion to Brandon Aiyuk and escaped the pocket to his left and scrambled for a 15-yard touchdown run.

It was a positive day for Lance, who also found Chris Conley for a touchdown in the second red zone period. The flashes and glimpses have always been there for Lance, and it’s evident he’s getting more comfortable the more he plays.

Still, there are plays that stick out like a sore thumb. Shanahan loves play-action passes to get the defense flowing one way, only to sneak a wide receiver going in the opposite direction. That was the case on this play, where Deebo Samuel had a step on the defense, but Lance airmailed the throw.

Digging Darnold

Darnold’s numbers will read 8-for-10, but a few of those were swing routes to running backs out of the backfield and a screen pass to Deebo Samuel. That’s not to take anything away from what Darnold did Sunday because he played well.

Full disclosure, when it comes to quarterbacks, I fall for variance. And if you know anything about Darnold, he’s the king of variance. Sam started the first period going 3-for-4 with a touchdown — a seed to Brandon Aiyuk on a “bang 8” in the red zone.

On the following play, Darnold may have missed Kittle on an easy pitch and catch out route by three yards. You may see some say Darnold threw for three touchdowns, but one of those was 100 percent a sack had it not been practice.

Be that as it may, Darnold escaped the pocket, rolled to his right, and hit Aiyuk streaking in the back of the end zone as Darnold threw the ball across his body. It was impressive, and so is his athleticism.

It doesn’t take long to see why the 49ers went out and signed the former No. 3 overall pick. Darnold found Aiyuk time and time again, as that combination wore out the defense running what’s called a backside dig route.

During his press conference after practice, Aiyuk called that his favorite route and said the offense refers to it as “free money, as long as we get it over the linebackers.” In fact, that route concept led to back-to-back explosive plays. Darnold threw it to Deebo Samuel the second time.

If Trey will be kicking himself later for missing Deebo underneath, Sam will do the same for not connecting in the low red zone to Jauan Jennings. The throw was maybe five inches too high, but that’s the difference between a touchdown and a field goal.

And then there’s Allen

Since this was my first practice, I was expecting to see a lot of Brandon Allen the way he was being portrayed. Allen only received eight or nine snaps, and completed three of his five attempts. So, like most QB3s.

Allen’s touchdown toss was superb, if for nothing else to know that he kept his composure. The offense was in shotgun, and the snap was low and slow. Allen caught the snap off a bounce, rolled out to his left, and hit Ray-Ray McCloud running a quick out route. Most quarterbacks would panic in the same situation, especially against this defense.

But it doesn’t take long to see Allen’s limitations. In an attempt to get Danny Gray involved, a slot fade was called. Gray had the cornerback beaten by a step or so, but Allen underthrew the ball so much that the defender was able to make up ground and break the pass up.

Best of the rest

If Aiyuk weren’t practicing, I’m not sure who the quarterbacks would target. It felt as if every time the quarterbacks dropped back when No. 11 was on the field, he was getting the ball. If you told me Aiyuk had 15 targets today, I’d believe you. Oh, and he caught every one, including three for touchdowns.

I asked Aiyuk how his conditioning level is compared to years past, as he gears up for a heavier workload this year. His answer was interesting:

“I feel good. We’ll see tomorrow once the pads come back on. It’s a little bit different when your mind’s not going a million miles an hour. It’s just less work that your body has to go through. It kinda feels like every plays not a thousand miles per hour, and full exertion on the body. So I’m able to get to spots and play football.”

Aiyuk went on to say a part of that is being more familiar with the playbook and how to play the game in general.

Jordan Mason had a remarkable run in the red zone, where he took a carry inside that looked like it would gain three yards, only to cut back and rush for another 15. But just as I was ready to drink the Kool-Aid, Mason fumbled in his next series.

Instantly, you could see a change in Javon Kinlaw’s body type. He looks slimmer. Almost as if he’s lost some baby fat. We’ll see if it leads to a change in his play, or to Kinlaw staying healthy. He pushed the guard into Lance’s lap, leading to Kinlaw batting a pass.

The best play from a defensive lineman came from Drake Jackson, where he peeled off the line of scrimmage and ran stride for stride with Elijah Mitchell down the sideline. Lance gave Mitchell a chance, but to no avail.

Nick Bosa remains AWOL as he awaits a contract extension. That means Jackson and Clelin Ferrell are running with the starting defense. If Jackson can wow with his athleticism with plays like that, we can go ahead and pencil him in as the starter.

After practice, Jackson said that he added weight and strength this offseason. But not because he felt like he’d play more this season. Jackson said it was to help get him through the season, which was an issue last year.

MVP of practice: Aiyuk, Brandon