It was like a final exam on the first day of school, but Bears rookie right tackle Larry Borom passed a very difficult test with flying colors.

Activated from injured reserve after missing six games, Borom made his first NFL start last Sunday against the 49ers, lining up frequently versus Pro Bowl defensive end Nick Bosa.

"There was zero hesitation from him," said offensive coordinator Bill Lazor. "There was zero fear from him. When we called quick protections, he went and was aggressive and got his hands on him. I thought for the scenario he went through of missing so much time and having played so little NFL football, to be up against such a good player and play the way he did was very good. You just have to expect it's only going to get better.

"He just revealed to us kind of what his makeup is, what his composure is. You hate to make too many broad statements over that first [start], but all signs are pointing in the right direction, so everyone was happy."

The 49ers moved Bosa from his usual spot at right defensive end to the left side so he could match up against the rookie instead of future Hall of Fame left tackle Jason Peters.

Borom said that facing Bosa "didn't really faze me that much. I knew I had to fall back on my technique and things I've been taught, and that's what I did."

Borom played 15 snaps at left tackle in the season opener against the Rams after Peters exited with a quad injury. But the fifth-round draft pick from Missouri hurt his ankle and was placed on injured reserve. During his recovery, he worked on his technique and pass sets at home, sending tape to offensive line coach Juan Castillo seeking feedback.

Borom, who told reporters that he moved his furniture, explained that he worked at home "just to be able to stay in that football mode, really, and keep being critiqued and be able to work on my technique and make sure I come back and it's not just, like, boom, a big blur with everything."

At Missouri, Borom made 19 starts at right tackle the past two seasons, including all eight games he played last year. He also opened two contests at left guard and one at left tackle, both in 2019. Playing in the SEC prepared Borom to compete in the NFL.

"Not only did he play at a high level [at Missouri], but he really didn't get beat a lot," Lazor said. "In college, he went against a lot of good pass rushers. Now, college and the NFL is different blocking the passer, but I think he blocked a lot of guys who ended up in the NFL and was a very productive player."

"Definitely the SEC prepares you for these types of moments," Borom said. "You're going up against great players day-in and day-out. Last year with it being just an all-SEC schedule [due to COVID-19], you had to be ready for everything."

That's also true of life in the NFL. After facing Bosa, Borom figures to be matched up against Steelers star pass rusher T.J. Watt Monday night in Pittsburgh. Watt entered Week 9 tied for second in the NFL with 8.5 sacks.

"He's a physical, fast player," Borom said. "He does things that other people can't."

Borom expects future Bears opponents to continue to line up their best pass rusher against him and not Peters like the 49ers did last Sunday.

"Everyone is top tier, so you've got to be ready to go against whoever you've got," Borom said. "But, I mean, I can see that being done. I'm just mentally preparing myself to do what I need to do."