"He was good," head coach Kyle Shanahan said when asked how Matthews looked this week during practice. "We messed with him because he had real fresh legs, which was good for him, especially compared to training camp. He looked real good.
"Jordan is a pro. He takes care of himself, so he came in in great shape, and didn't miss a beat."
Chris Biderman of the Sacramento Bee asked Shanahan if Matthews is in a position where the coach would feel comfortable having him active so soon after rejoining the team.
"Oh yeah, definitely," Shanahan responded. "Definitely comfortable with that."
Matthews, 27, is in his sixth NFL season and is one of the 49ers' most experienced receivers. Only Marquise Goodwin has been in the league longer.
The Philadelphia Eagles made Matthews a second-round selection out of Vanderbilt in 2014. He has caught 270 passes for 3,255 yards with 22 touchdowns through his five NFL seasons.
The 49ers initially signed Matthews on March 14 but released him as part of the team's 53-player roster cutdown at the end of August, a move that general manager John Lynch admitted was "a very tough decision."