SANTA CLARA, Calif. -- With their top returning wide receiver, Michael Crabtree, out indefinitely with a torn Achilles tendon, it was good news Thursday for the San Francisco 49ers when quarterback Colin Kaepernick said he was thrilled with the development of his remaining receivers.
He said he was impressed with the development of A. J. Jenkins, last year's first-round draft pick who was active in only three games during the 2012 season.
"Leaps and bounds ahead of where he was last year," Kaepernick said of Jenkins' improvement. But this isn't surprising to Kaepernick, who spent two months during the offseason working out with Jenkins and getting to know each other.
Offensive coordinator Greg Roman definitely noticed Jenkins' improvement.
"The last two days of last week, he had the two best days he's had since I've been here," Roman said. "Just made some clutch catches for us when we were moving the ball. Just made plays, did all the right things, made plays when he had the opportunity and he just needs to continue doing that."
Jenkins said bonding with Kaepernick off the field had a major impact with how they work together on the field.
"I never really hung out with him outside of football, so I was just going down there with him, chilling with him, staying with him, getting to know who he is and who I am as a person," Jenkins said.
"I think there's a natural process that goes on, a comfort level and that's something that's growing all the time and needs to continue to grow," Roman said.
Jenkins said he set his sights on playing more this year, and that was long before Crabtree was injured.
"My mindset going into this offseason was just trying to play more, regardless of whether Crabtree was hurt or not," he said. "It's unfortunate that he got an injury, but my mindset didn't waver at all because he got hurt."
Both Kaepernick and Jenkins said they were impressed by veteran wide receiver Anquan Boldin, previously of the Baltimore Ravens.
"He shows his veteran awareness," Kaepernick said. "I learn from him just watching him run a pattern."
--Cornerback Nnamdi Asomugah is still learning defensive coordinator Vic Fangio's system and his role isn't clear, but that hasn't stopped him from taking on a leadership role.
"I've always been a leader throughout my career, I would definitely say that," Asomugah said. "The guys have looked at me in that way already and I'm just stepping foot here for a couple months."
--Rookie quarterback B.J. Daniels spent some time working at wide receiver and on special teams. He doesn't anticipate supplanting LaMichael James as a returner, but has been taking reps there in practice. Daniels has never played a position other than quarterback going back to his youth.