(Sports Network) - The San Diego Padres and Arizona Diamondbacks have combined to win three of the last four National League West titles, but reaching the postseason seems like a longshot for both teams this season.

The two foes will be attempting to avoid the division basement when they begin a three-game series tonight at Chase Field.

San Diego, the 2005 and 2006 NL West champions, has fallen on hard times in recent years. The Padres lost 99 games in 2008 and has improved just slightly over the course of this season, having compiled a 35-46 record entering tonight's play.

Arizona, which captured the division crown with a 90-win campaign in 2007, has had an even greater descent. The Diamondbacks' 33-49 mark is the second-worst in all of baseball and is good for last place in the NL West standings, 2 1/2 games behind the Padres.

The Diamondbacks do enter this series on a high note, however, after taking the final two tests of a three-game series at Colorado over the weekend. Arizona prevailed by a 4-3 count in Sunday's finale, with Felipe Lopez's tie- breaking RBI single in the seventh inning accounting for the winning margin.

"We played [Friday's] game sloppy, and to respond with two wins is a nice feeling going home," said D-Backs manager A.J. Hinch, whose club completed a six-game road trip with a 3-3 record.

Arizona trailed 3-0 after five innings and did not record a hit until Mark Reynolds blasted a three-run homer in the top of the sixth to tie the score. The long ball was the 24th of the season for Reynolds, one of five candidates eligible to be voted for the final spot on the NL All-Star squad.

Dan Haren was named to the NL All-Star team on Sunday, and the Diamondbacks ace backed up the honor with a strong performance on the mound. Haren (8-5) held the Rockies to three runs -- one earned -- and struck out six over the first six innings before turning the game over to the bullpen, where four Arizona relievers combined to throw three scoreless innings to preserve the lead.

Outfielder Justin Upton was also selected to represent Arizona in this year's Midsummer Classic, to be held at St. Louis' Busch Stadium on July 14.

The Padres have begun July with losses in four of their first five games, including Sunday's extra-inning setback to NL West-leading Los Angeles. James Loney homered to lead off the top of the 13th and the Dodgers overcame a ninth-inning collapse to post a 7-6 win.

San Diego trailed 6-1 entering the bottom of the ninth, but erupted for five runs to send the contest into extra frames. Everth Cabrera tied the score with a two-out, two-run single off Dodgers All-Star closer Jonathan Broxton.

"Five runs in the ninth against Broxton, who is one of the best closers in the game? Phenomenal comeback," remarked Padres manager Bud Black.

Chase Headley had a solo homer during San Diego's ninth-inning rally, while Kevin Kouzmanoff homered earlier in the day for the Padres.

Before the game, the Padres learned that first baseman Adrian Gonzalez and closer Heath Bell were selected to this year's NL All-Star team. Bell leads the Senior Circuit with 23 saves at the moment, while Gonzalez's 24 homers are tied with Reynolds for second-most in the league.

Gonzalez will be taking his swings tonight off Jon Garland, who takes the mound for Arizona looking to halt a long winless spell. Since earning his fourth victory of the season on May 19, the veteran right-hander has gone 0-6 with a 4.91 ERA over an eight-start stretch, and the Diamondbacks have lost every one of those games.

Garland did pitch well enough to win his last time out, as he limited Cincinnati to one run over six innings this past Wednesday. He received zero offensive support, however, and wound up on the short end of a 1-0 decision.

The 29-year-old has faced the Padres in San Diego twice previously this season, with much different results. Garland twirled seven shutout innings in a May 6 win at Petco Park, but was tagged for six runs and walked five over 6 2/3 frames in a 6-3 loss there on June 8.

For his career, Garland is 2-2 with a 2.51 ERA in four overall starts against San Diego.

While Garland hasn't been on the winning side in quite a while, San Diego's Walter Silva enters this evening's start still in search of his first big- league victory. The former Mexican League hurler is 0-2 in five 2009 starts and has surrendered 25 runs (21 earned) in 21 1/3 innings pitched over that span.

Silva last took the hill on Wednesday and was reached for six runs (3 earned) over four innings in a home loss to Houston. The right-hander has not pitched more than 5 1/3 frames in any of his starts and has issued 14 walks in his 21 1/3 innings of work.

This will be the first career appearance against Arizona for Silva, who has allowed a whopping 14 runs (13 earned) and 12 hits over just seven innings in a pair of road starts this year.

San Diego has won five of the first nine meetings with the Diamondbacks this season and took two of three matchups at Chase Field from May 25-27.