Zach Davies hopes to end a difficult season on a positive note Sunday when the Arizona Diamondbacks seek a series win over the host San Francisco Giants.

One year after they captured the National League West crown and a spot in the playoffs with 107 wins, the Giants (79-79) need at least two winsin their final four games to finish with a .500 record this season. They will close the year with three games in San Diego.

San Francisco hasn't played .500 ball against Arizona (73-85), which clinched the season series with an 8-4 win Saturday. The Diamondbacks have won 10 of the 18 meetings against the Giants.

While the rest of the D-backs have a three-game trip to Milwaukee starting Monday in an effort to put a positive closing spin on the season, Davies (2-5, 4.18 ERA) will get his last opportunity in the series finale vs. the Giants.

Davies enters the game saddled with the majors' longest streak of winless starts -- a 19-game stretch dating to May 13. He's gone 0-4 with a 4.40 ERA in those 19 starts.

The 29-year-old will face the Giants for the second time this season. He received a no-decision on Aug. 17 despite allowing one run on five hits in five innings.

Davies is 1-4 with a 3.70 ERA in nine career starts against San Francisco.

The Giants have 20 hits in the first two games of the series, but the Diamondbacks have held them without one of their specialties -- the bunt single. The Giants entered the weekend tied with the Washington Nationals for the most bunt hits in the majors with 27.

They're not likely to add to that total with the athletic Davies on the mound, catcher Carson Kelly noted.

"It takes away some of those bunts," Kelly said of what he considers to be a fifth infielder when either Davies and Zac Gallen is on the mound. "The balls in the middle between first and the mound, they can get to. Those make a big difference. One less guy on base ultimately helps us win games."

Davies has made only one error in the last three seasons.

The Giants would love to do the same thing they did the last time they lost to the Diamondbacks -- respond with a string of wins.

San Francisco had a five-game winning streak snapped in Arizona eight days ago but bounced back with five more victories before Saturday's setback.

The Giants will search for a new winning streak without right-hander Logan Webb, who had been the scheduled starter for the home finale. San Francisco manager Gabe Kapler announced Saturday that Webb will be shut down for the rest of the season for load-management purposes.

Webb will go on the injured list to create room on the roster for another pitcher but insisted the listed "sore lower back" is not an issue.

"I feel fine. I could easily pitch," he said. "I think everyone here has started dealing with some stuff. I'm actually really excited about (finishing the season healthy)."

Giants left-hander Scott Alexander (0-0, 1.10) will make his third start of the season as an opener. He's faced the Diamondbacks 18 times in his career, just twice as a starter, and has gone 0-1 with a 6.75 ERA.