Despite being 9-14 and sitting fifth in the National League Central, the Astros have outscored opponents, 104-100.
Mills said he sees that as a sign and hopes Monday's win over the Mets to open a nine-game homestand is the start of that turnaround.
"A couple of guys today were talking about the run differential and we're still scoring more runs than our opponents," Mills said Monday. "What that tells me is we want to be able to get something for being able to put those runs across. We're right there. We're in those ballgames and just need to get over that hump, and that's what we want to do this homestand is to score those runs and win those games and get over that hump."
The Astros have to do that on Tuesday against the Mets, who have won five of their last seven, and left-hander Jon Niese. Niese looks to continue the Mets' recent success, as he takes the mound for his fifth start of the season. The lefty has impressed in the season's early going, tossing four quality starts.
He's also had success in three career starts against the Astros, going 1-1 with a 1.80 ERA. The lefty's lone loss against Houston came last year, when he allowed two runs on seven hits and walked five in six innings. Current Astros are batting just .156 (5-for-32) against Niese.
Mets: Wright streaking
Despite striking out three times Monday, third baseman David Wright has a seven-game hitting streak, in which he's batting .417 with six RBIs.
Mike Baxter has three hits in his last four pinch-hit appearances and is hitting .455 (5-for-11) in such situations.
Following Monday's one-run loss, the Mets are 6-2 in one-run games.
Astros: Happ on the hill
Left-hander J.A. Happ takes the mound for the Astros on Tuesday, as he looks to rebound from his first non-quality start of the season. In his last outing against the Brewers, Happ allowed four runs in five innings. He's 2-2 with a 4.82 ERA in eight career appearances against the Mets.
Outfielder Jordan Schafer has reached base in 23 straight games to open the season, tying him with Ricky Gutierrez (1998) for the second-longest stretch to start the season in Astros history. Denis Menke owns the club record for reaching safely in his first 25 games in 1969.
The Mets are making their final trip to Houston in the Astros' final season in the National League. New York is 108-174 all-time in Houston, including 20-21 at Minute Maid Park.
Wright is hitting .462 (6-for-13) with three homers against Happ.