A rib injury to young star Colby McKercher forced North Melbourne into an early sub change in their bout with Geelong on Sunday.

McKercher was left hampered after a collision with Cats forward Jeremy Cameron, with the teenager eventually making his way from the field to gain medical treatment.

The No.2 pick from last year's draft was assessed further in the Roos' rooms ahead of the quarter-time break, with North Melbourne making the decision ahead of the second term to replace McKercher in the match.

The club soon confirmed McKercher was taken to hospital following the knock.

Fringe midfielder Charlie Lazzaro was brought into the contest, with North Melbourne forced to play without an extra man for three-and-a-half quarters against Geelong.

Mckercher managed just half a quarter before being subbed out, with the Tasmanian collecting one handball and a clearance before his afternoon was brought to an abrupt end.

Even minor damage to the ribs could force McKercher to the sidelines for his side's upcoming clash with Hawthorn, which will take place at Marvel Stadium next Sunday.

Geelong WON BY 75 POINTS
GMHBA Stadium