The Phils, who are four games back of the second National League Wild Card spot, have 15 games remaining, and nine of them will be on the road, where they are 36-37 this season. They have not been above .500 on the road since June 17 (19-18).
The Phillies begin a three-game series in New York vs. Mets on Monday and finish the season with six road games, three each at Atlanta and Washington.
Philadelphia will need to shake off a rough series in Houston, where it dropped three of four games, including Sunday's 7-6 decision.
"We can turn it around," manager Charlie Manuel said. "We've been in tougher situations than this, quite a few times. Basically what we've got to do is we've got to keep going and keep trying. You get tested all the time."
To calculate a team's magic number, take the number of games it has remaining and add one. Then subtract the difference in the number of losses between that team and its closest pursuer.
A tiebreaker game will be played to determine a division winner, even if the tied clubs are assured of participating in the postseason. If a division championship tiebreaker is necessary, the head-to-head record between the clubs will determine home-field advantage. If the head-to-head record is tied, then the division record will be the next tiebreaker.
If two clubs are tied for the two Wild Card berths, home-field advantage will be determined by the head-to-head record between the clubs. If the head-to-head record is tied, then the division record will be the next tiebreaker.