The injury occurred during Thursday night's preseason game against the Houston Texans. According to NBC Sports Bay Area, Samuel is unlikely to practice this week but should be good once the 49ers start preparing for Week 1 against the Chicago Bears.
Also sitting out the session is tackle Trent Williams, who is "under the weather."
Elijah Mitchell returns
Cornerback Charvarius Ward wasn't the only previously-injured player who returned to practice. Starting running back Elijah Mitchell rejoined his teammates today after missing the entire preseason with a hamstring injury.
Two O-lineman remain sidelined
Right tackle Mike McGlinchey remains sidelined as he attempts to return from a knee injury, per multiple reports. Offensive lineman Daniel Brunskill was among those observing practice from the side.
Jimmie Ward sighting
As previously reported, safety Jimmie Ward will start the season on injured reserve due to a hamstring injury, missing at least the first four games of the regular season. He was seen working on the side with the 49ers training staff.
The 49ers are scheduled to hit the practice field again on Monday and Tuesday before taking Wednesday off. The team has two weeks until its regular-season opener at Soldier Field.