The prognosis keeps improving for Geelong ruckman Brad Ottens, with scans on his injured right knee on Monday indicating he will miss less football than first thought.

The star big man has been diagnosed with a slight grade one medial ligament strain, with the Cats estimating he will spend two to four games on the sidelines.

The club had said after Saturday's win over Richmond at Skilled Stadium that they expected Ottens to be out for four to six matches.

That was already an improvement on their initial fear that he had injured his posterior cruciate, which would have sidelined him for several months.

But the news was much gloomier for the club's No.1 draft pick, Mitch Brown.

The 18-year-old key forward prospect has been ruled out for the rest of the season after breaking the fibula in his left leg in a VFL practice game.

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