(Photo credit: Jeff Curry-Imagn Images)

The Arizona Diamondbacks and St. Louis Cardinals open post-All-Star Game play this weekend in a series that could help both define their buy/sell decisions at the July 31 trade deadline.

The Cardinals (51-46) are 6 1/2 games behind the first-place Chicago Cubs in the National League Central but only 1 1/2 games behind San Diego for the third and final NL wild-card spot.

The Diamondbacks (40-57) are in a little deeper hole - fourth in the NL West, four games behind the Cardinals and 5 1/2 games behind the Padres in the wild-card race. General manager Mike Hazen is clear-eyed about it.

'With the position we've put ourselves in, we need to play pretty exceptional to move back up from where we are now,' Hazen told reporters.

The Cardinals will start right-hander Andre Pallante (5-5, 4.49 ERA) in the opener of the three-game series Friday in Phoenix. Brandon Pfaadt (9-6, 5.16) is slated to start for Arizona.

St. Louis swept the first series at Busch Stadium, May 23-25, winning each by one run.

Both teams ended the All-Star break on a downer, losing eight of 12 while failing to make up ground.

The D-backs split four-game series against division rivals San Diego and San Francisco and lost two of three to Kansas City and the Los Angeles Angels.

The Cardinals were a season-high nine games above .500 before they were shut out three straight times in a sweep at Pittsburgh from June 30 to July 2. They also lost series to the Cubs and Atlanta.

'I do feel like where we are in the week leading up, or the 72 hours leading up to the trading deadline, may affect how we make our decisions,' Cardinals president of baseball operations John Mozeliak said before the break.

'We're still trying to balance today's success with ultimately having long-term success. I hope we have really hard decisions to make come July 31, because that means we're playing well.'

Both teams had some good moments at the All-Star Game.

D-backs outfielder Corbin Carroll hit a 414-foot homer and walked, second baseman Ketel Marte had a two-run double off Tarik Skubal, and Eugenio Suarez made a nice bare-handed pickup and throw on a slow roller to third.

Cardinals second baseman Brandon Donovan had two hits and scored a run after replacing Marte. He was the only All-Star with multiple hits.

Both teams have nagging injury concerns. Suarez was hit by a pitch in the left hand in the eighth inning of the All-Star Game, but he said X-rays were negative. Cardinals third baseman Nolan Arenado missed seven of the last 12 games because of finger and shoulder issues.

Pallante was figuratively clobbered in his last start, giving up seven runs and eight hits in six innings of an 8-2 home loss to Washington. He had given up three runs or less in his previous five starts, including a no-decision in a 1-0 at Pittsburgh as he gave up one hit in seven innings.

He is 1-0 in seven games, all in relief, against Arizona.

Pfaadt got the win in his last start, going eight innings in an 8-2 win over the San Diego Padres. He has faced the Cardinals three times, giving up 11 runs in 17 innings (5.82 ERA).

--Field Level Media