Jeff Samardzija's insistence on hitting the open market this offseason has led to him reportedly tabling talks for an extension with both Chicago clubs in just over a year.

It's also part of the reason he's riding out the last season of his contract on the South Side rather than potentially contributing to the Chicago Cubs' resurgence.

Samardzija tries to cool off his former team as the Chicago White Sox host the North Siders in the opener of a three-game series Friday.

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Cubs management reportedly offered Samardzija a five-year, $85 million extension that he rejected last year before the right-hander posted a 2.83 ERA in 17 starts. With the Cubs on their way to a last-place finish, they dealt Samardzija and Jason Hammel to Oakland on July 4, 2014, for a package of prospects that included Addison Russell, a regular starting infielder for the Cubs (65-48) since making his debut April 21.

Samardzija (8-7, 4.62 ERA) might be hard-pressed to find an offer better than the Cubs' now. He hasn't discussed an extension with the White Sox (54-58) since they acquired him from the A's during the offseason and hasn't helped his cause by allowing at least four runs in 11 of 23 starts.

He pitched a season-low 4 2-3 innings in each of his last two, allowing nine runs in a loss to the New York Yankees on Aug. 2 and seven in Saturday's defeat at Kansas City.

It's the first time Samardzija has gone fewer than five innings in back-to-back outings since he became a full-time starter with the Cubs in 2012.

"You play two good teams, and if you aren't on your game, it's going to come back to get you," Samardzija said. "You've got five days and you start again."

Samardzija now makes his first start against his former team after spending parts of seven seasons with the Cubs, who have won seven in a row and 13 of 14 to move into the NL's last playoff spot while gaining ground on wild-card leading Pittsburgh.

The last six victories have come with Starlin Castro starting on the bench and Russell shifting from second base to shortstop. Chris Coghlan has moved to second to open a spot in left field for rookie Kyle Schwarber.

Schwarber snapped an 0-for-11 slump by hitting two of the Cubs' five homers and driving in four runs in Thursday's 9-2 win over Milwaukee.

The Cubs haven't won eight straight since a nine-game run May 26-June 3, 2008.

''That's the mindset that we need to have, is we're playing in the playoffs every day,'' Schwarber said.

The White Sox dropped eight of their previous 10 before Avisail Garcia's RBI double in the 13th gave them a 3-2 win Wednesday and three-game sweep of the Los Angeles Angels.

They're attempting to catch the Angels for the second wild card but also have to jump five other teams in a tight race.

"(The Cubs) are playing well, so you want it to be fun and meaningful games," manager Robin Ventura told MLB's official site. "I think we're getting to that point."

The White Sox took two of three at Wrigley Field from July 10-12, including a 1-0 win in the opener. Right-hander Kyle Hendricks (6-5, 3.73) has gone 2-1 with a 4.34 ERA in five starts since tossing seven innings for the Cubs in that contest, and he'll oppose Samardzija in this matchup.

Ventura said designated hitter Adam LaRoche, mired in a 1-for-16 slump, will start after pinch-hitting in the 9th on Wednesday.

The Cubs have won five of seven at U.S. Cellular Field since 2012.

''I know the atmosphere's going to be great,'' Cubs first baseman Anthony Rizzo said.