The San Francisco Giants hope a visit from the San Diego Padres helps get them headed back in a positive direction in the National League playoff race when the clubs open a four-game series Thursday night. Both teams will be counting upon newcomers to play key roles as the Giants seek to build upon a 9-6 lead in the season series in the final set between the NL West rivals. The Giants opened a six-game homestand with a pair of costly losses to the Arizona Diamondbacks on Monday and Tuesday, defeats that dropped San Francisco six games out of the final NL wild-card spot with just 30 games remaining.