It was Peterson's fifth home run of the year. He has now homered in back-to-back games after going 27 games without one.
Spangenberg has not played since June 27 due to a bone bruise in his left knee.
Infielder Jose Ramirez was summoned from Triple-A to take Kipnis' spot on the roster. Kipnis is expected to miss 2-3 weeks, according to the Cleveland Plain Dealer.
Lingering back problems caused Panik to miss three of the last five games, including Sunday's contest.
Panik will travel back to the Bay Area to undergo testing, the San Francisco Chronicle reported. He'll have an MRI and CAT scan.
To replace him on the active roster, the Giants recalled infielder Kelby Tomlinson from Triple-A Sacramento.
Tomlinson is hitting .316 in 33 games at Sacramento.
Panik is batting .333 (23 for 69) with one home run, four doubles, five RBI, 15 runs, six walks and four strikeouts in his last 17 games.
Utley is on the 15-day disabled list with an ankle injury.
Drew is hitting .354 with 11 hits, two doubles, a triple, a home run and seven RBI over his last 10 games.
His biggest hit came when Peterson hit a three-run home run off Adam Morgan in the fifth inning. It was his fourth home run of the season.
Prior to Sunday's win, Peterson was hitting .132 with one RBI in his last 11 games.
Francona added that he wanted to talk the situation over with the medical staff and general manager Chris Antonetti before a decision is made.
Kipnis was on one of his many hot streaks this season until arriving for the team's current series in Oakland. He is 1-for-12 against the Athletics, but still boasts a slash line of .326/.401/.477 on the year.
Spangenberg will return with a slash line of .254/.304/.356 and 44 strikeouts in just 177 at-bats.