By Chris Rosvoglou After missing the first two games of the regular season due to a knee injury, Los Angeles Rams wide receiver Van Jefferson has been placed on injured reserve. Jefferson underwent multiple knee surgeries in the offseason. The second procedure took place after he tweaked his knee in training camp. Clearly, Jefferson’s knee hasn’t fully healed yet. Since the Rams placed Jefferson on injured reserve, they’ll be without the Florida product for at least the next four weeks. In addition to placing Jefferson on injured reserve, the Rams signed defensive back Grant Haley to their act…