Donald J. Trump will not cross the Florida state line to campaign with Herschel Walker during the final week of the Georgia Senate runoff election, after both camps decided the former president’s appearance carried more political risks than rewards, campaign officials for the two Republicans said on Monday.

Instead of holding one of his signature campaign rallies, Mr. Trump is planning a call with supporters in the state and will continue sending online fund-raising pleas for Mr. Walker, two people with knowledge of the planning said.

The decision to keep Mr. Trump out of the spotlight was a response largely to the former president’s political style and image, which can energize his core supporters but also motivate Democratic voters and turn off significant segments of moderate Republicans.