Wild center Mikko Koivu, who has missed much of the past two months with a shoulder injury, is looking at sitting out for an even longer stretch. General manager Chuck Fletcher said on Tuesday night that the captain re-aggravated his shoulder, which he originally injured on Jan. 14 in St. Louis. Koivu returned to the lineup on Feb. 9, but he got hurt again when former Blue Jackets forward Jeff Carter tackled him on Columbus' empty-net goal on Feb. 11.