Bielak will serve as a reliever to begin the regular season, Brian McTaggart of MLB.com reports.
Bielak was in the mix to start the Astros' fifth game of the regular season Monday, but manager Dusty Baker said Wednesday that Luis Garcia will serve as the team's fifth starter while Jake Odorizzi (conditioning) is unavailable. Bielak should take on a multi-inning role out of the bullpen this season. The right-hander made five appearances (two starts) this spring and posted a 4.50 ERA and 1.00 WHIP in 16 innings.