Seager was pulled Friday night after jamming his glove into the ground diving for a hard grounder by the Chicago Cubs' Javier Baez. Seager removed his mitt and favored his wrist and hand while Baez ran out a double. He left the game after one more batter.
Seager said postgame that he was fine, and the Mariners said the former All-Star and Gold Glove winner didn't seek medical treatment Friday night.
That changed Saturday, when Seager was sent for X-rays and had the hand heavily wrapped. The X-rays were negative.
It's unclear if the injury will risk Seager's status for Seattle's season-opening series in Japan. The Mariners will fly to Japan on Thursday before opening the season with two games against Oakland on March 20-21 at the Tokyo Dome.
The 31-year-old Seager has hit at least 20 home runs in seven straight seasons.