Greinke, who's already been one of the league's top fantasy baseball starters, could become an even bigger asset during the season's stretch run following the move.
The 35-year-old Florida native was putting together another strong season for Arizona. The six-time All-Star selection posted a 2.87 ERA (sixth among qualified MLB starters) and 0.94 WHIP (first) while striking out 128 batters in 141 innings across 22 starts.
Although it'd be hard to expect more in terms of ERA and WHIP, there are other reasons for optimism from a fantasy perspective.
First, he's going from the league's 12th-ranked offense in OPS to the third-ranked Astros. And it's a group that could improve with shortstop Carlos Correa recently returning from an extended stint on the injured list and star prospect Kyle Tucker tearing up Triple-A pitching.
Second, the Astros' staff has shown a propensity of improving starters' strikeout rates.
Gerrit Cole went from 8.7 strikeouts per nine during his final season with the Pittsburgh Pirates in 2017 to 13.3 K/9 this year in Houston. Even Justin Verlander, long known for his punchout ability, posted a career-best 12.2 K/9 figure for the 'Stros last year.
So Greinke should find himself in position for more wins, which remains relevant in most fantasy formats despite its decreased real-world meaning, and could also see an uptick in his strikeout numbers over the next couple of months.
It'll make the veteran right-hander one of the top handful of fantasy starting pitchers the rest of the way.