Houston (10-20) is seeking its third series victory, with its last one coming when it took two of three at Seattle (13-15) from April 21-23.
McHugh (2-0, 0.59 ERA) made his club debut in the middle game of that series, pitching 6 2-3 scoreless innings with a career-high 12 strikeouts in a 5-2 victory. Only J.R. Richard had more strikeouts in an Astros debut with 15 on Sept. 5, 1971.
McHugh eventually extended his season-opening scoreless innings streak to 15 1-3 before he gave up one run last Sunday. He came within an out of a shutout in a 5-1 win over Oakland in his home debut.
"As I kind of got momentum, I started to roll with it, and it got easier to make pitches and kind of feel the flow and go with it," he said.
The right-hander only joined the rotation due to an injury to Scott Feldman. Now, he has earned a permanent spot.
"I don't think he put us in a tough spot; I think he put himself in a really good spot," manager Bo Porter said. "Performance pretty much speaks for itself. This guy has earned the right to get the ball the next turn."
Seattle will counter with Maurer (0-0, 6.75), who is 0-3 with a 6.10 ERA in six career road starts - all losses for the Mariners.
Maurer has an even bigger problem Sunday since he is 0-2 with a 27.00 ERA in two career outings against the Astros. He failed to get out of the first inning April 9, 2013, in his second career start and lasted three innings Sept. 11.
The right-hander has failed to complete five innings in two 2014 starts, giving up five runs over 3 2-3 in a 6-5 win over Texas last Sunday. This is his third straight Sunday start.
Maurer will get his first look at Houston rookie George Springer, who rested in Saturday's 9-8 loss for the Astros after starting 14 straight games. Springer, called up from Triple-A Oklahoma City on April 16, singled home the winning run in the 11th inning in Friday's 5-4 victory.
''It's more of just a breather,'' Porter said.
Matt Dominguez batted cleanup with Springer out of the lineup. Dominguez is 3 for 3 with two doubles against Maurer.
Seattle evened the series thanks to an eight-run seventh inning outburst Saturday capped by Justin Smoak's two-run homer. Manager Lloyd McClendon was ejected in that frame.
McClendon benched outfielder Abraham Almonte, who is in a 4-for-37 slump.
''That's why he's sitting, because it's not working,'' McClendon said. ''It's that simple. He's not playing because he's not producing.''
Third baseman Kyle Seager is hitting .394 during an eight-game hitting streak that has coincided with this 6-2 stretch for Seattle.