The pitch that hit Jose Altuve on Saturday fractured the Astros second baseman’s thumb:

There is no timetable for his return, according to Brown. The Astros will announce a prognosis after the surgery, which will happen in the coming days. 

ESPN.com

Thumb injuries can affect performance even after they are healed.

The Astros plan to replace Altuve with Mauricio Dubon. Using the Lineup Analysis Tool (LAT), it looks like Dubon would cost the offense 0.22 runs per game, which would be 35 runs over a season. That’s about three to four wins.