Arik Armstead week-to-week with hamstring injury

AP

The 49ers announced that five players will be joining the team for practice after opening training camp on injury lists along with news about another member of the squad who will be sidelined for a while.

Defensive lineman Arik Armstead has a hamstring injury and the team describes his timeline to return to action as “week-to-week.” Injuries have been a recurring theme for Armstead of late as a shoulder injury and a broken hand have conspired to limit him to 14 games the last two seasons.

On the positive side of the injury news, the team announced that guard Jonathan Cooper, wide receiver Trent Taylor and linebacker Dekoda Watson have been activated from the physically unable to perform list. Safety Marcell Harris and linebacker Malcolm Smith will join them at practice as they have been activated from the non-football injury list.

The 49ers also announced that guard Joshua Garnett is day-to-day with a knee injury and that tight end Cole Hikutini will be out the rest of this week due to a groin injury.