“We hadn’t seen him out there in a while going with the team,” Shanahan added.
“Wednesday, he looked great, Thursday, he was even better, and today he was even more comfortable. It made the decision pretty easy.”
Pearsall was drafted in the first round by the 49ers out of the University of Florida, and big things were expected of him in making the step up to the NFL.
But after dealing with a shoulder injury in the summer, he was then shot in the incident in San Francisco’s Union Square, when he was taken to hospital with a bullet wound to the chest.
Pearsall was released after just one night in hospital as a lucky escape saw the bullet miss any vital organs.
And he impressed his new team-mates immediately upon his return to training.
“He’s doing a really good job, obviously being back and just bringing the juice, going really fast in and out of his cuts and creating some really good separation,” said 49ers quarterback Brock Purdy.
“When you’ve got a guy like Ricky that can win man-to-man match-ups and then also open up some other guys too, that’s always a good thing. So I’m excited to see what he does.”
Listen to live commentary as the Kansas City Chiefs visit the San Francisco 49ers this Sunday on BBC Radio 5 Sports Extra and the BBC Sport website and app (from 21:00 BST).