Nick Bosa injured his calf while performing high knees during an individual warmup before the San Francisco 49ers began their official stretching routine, coach Kyle Shanahan said Friday. The injury occurred shortly before practice started and was not sustained during a team drill.
Shanahan estimated that Bosa could be out for a few weeks but did not provide a firm timetable. He also said the injury is not expected to create a lasting problem and expressed confidence that the defensive end will return this season.
The injury adds to a difficult stretch for San Francisco’s defensive line. Shanahan said six of the 10 defensive linemen who made the team have been lost during the past two weeks, a situation he described as unusual in his experience. The number of available players leaves the team with enough healthy defensive linemen for its starting group and limited depth.
The 49ers had not decided whether Bosa would be placed on injured reserve. Shanahan said Bosa and several other injured players were being evaluated for that designation, but the team would not be able to place all of them there. Avoiding injured reserve would mean Bosa would not be subject to the designation’s mandatory four-game minimum, although his exact status was not yet clear.
Friday’s injury report listed Mike Evans as a full participant despite his questionable designation for the game against the Arizona Cardinals. Evans is listed with a hip injury. Rookie Romello Height was ruled out after undergoing hand surgery earlier in the week, while Bosa, James Thompson Jr. and Demarcus Robinson did not practice.
