Sporting Kansas City says rookie defender Aurelien Collin is expected to miss four to six weeks because of two small fractures in his lower back.

The team said Thursday that Collin was injured Saturday in a 4-2 win over Toronto FC.

Collin has started 15 games in his first Major League Soccer season after signing in April.

Two of his three goals have been match-winners during the club's current 12-game unbeaten streak. Team spokesman Rob Thomson says Collin is a big, physical player who has helped solidify the team.