The 49ers' offense hasn't been the explosive attack many pictured coming into the season.
While Deebo Samuel has been outstanding, the 49ers' offense as a whole has started slowly and lacked big plays in the passing game. Brandon Aiyuk's quiet season has played a big part in San Francisco's lackluster offensive start, and coach Kyle Shanahan knows the 49ers can't reach their ceiling without Aiyuk -- or someone -- filling that No. 2 receiver role opposite Samuel.
"No, definitely not," Shanahan told KNBR's "Tolbert, Krueger & Brooks" on Thursday. "And if not him, somebody. We need a lot of guys to step up. There's five eligibles. [Deebo] has done a real good job. We need [George] Kittle to step it up, too. I know how much Kittle has been battling his injuries, so that's been the toughest thing with him. [Mohamed Sanu] has done some good things in the slot.
"Whether it's Aiyuk, whether it's [Trent] Sherfield, Jauan Jennings has done some good things for us. But also, Raheem [Mostert] was kind of a weapon, not just as a runner, but also as a third-down back who could do some stuff in the pass game. We kind of lost that where [Kyle Juszczyk] has stepped it up and done real well in that role, but the more weapons you can have out there is really when you can do everything."
After catching 60 passes for 748 yards and five touchdowns during his rookie season, Aiyuk has been almost non-existent through four games this season, with just six receptions for 58 yards and one TD.
The Arizona State product split snaps with Sherfield in Week 1 and received zero targets from quarterback Jimmy Garoppolo. While he has seen his snap count tick up since then, Aiyuk's production hasn't risen with his playing time.
Shanahan knows how dangerous Aiyuk can be, but the coach is preaching patience with his young wideout.
"We know Aiyuk can be a weapon," Shanahan said. "That's why we've got him here. I'm a big fan of Aiyuk, but he's not there yet. He's still coming along. At times, he does it at a high level. We just want him to be a little bit more consistent, and I think his time will come. It's a matter of time.
"He's too good of a player for it not to be, and he's working at it, so everyone, just be a little patient with him."
With Aiyuk a non-factor, the 49ers' passing game has been reliant on Samuel to provide even more juice as the No. 1 receiver. The South Carolina product has been the team's MVP through the first four games, as he leads the NFL in receiving yards with 490 yards.
Samuel is turning into a complete receiver and already has developed good chemistry with rookie QB Trey Lance, who had to enter in relief of an injured Garoppolo in Week 4. Lance hit Samuel for a 76-yard touchdown on a busted coverage by the Seattle Seahawks, and later found Samuel again for an 8-yard score in the fourth quarter.
Samuel has been a dynamic threat through four games, and the 49ers will get more from Kittle when he's healthier. But in order for the 49ers' offense to live up to its potential, Shanahan needs another consistent outside threat to emerge.
Aiyuk has the talent to fill that role, but the 49ers still are waiting for everything to click for the young receiver.