Kawasaki Frontale's Japan international Yu Kobayashi will be out for six weeks after undergoing surgery to repair meniscus damage in his right knee, the J. League club said Tuesday.
Kobayashi was hurt while warming up for Wednesday's 1-0 home defeat to Sanfrecce Hiroshima. The 27-year-old forward had the operation on Monday.
Kawasaki is currently fourth, seven points off the pace of Urawa Reds with six games remaining in the first stage.