Minnesota Vikings wide receiver Justin Jefferson will undergo imaging tests in four weeks to determine the severity of his hamstring injury. Doctors believe he will be sidelined for four to six weeks. The Vikings placed Jefferson on injured reserve and are preparing to be without him for at least four weeks. Head coach Kevin O'Connell is hopeful that Jefferson can recover quickly and return to full speed. In the meantime, wide receivers N'Keal Harry and Trishton Jackson have been elevated from the practice squad to provide depth.