Reports in the Standard indicate that Mr Odinga, who traveled to Europe on Monday, would pass through Germany to meet his running mate.
After the meeting, the two leaders are expected to travel back home on Thursday night and arrive in Nairobi Friday morning.
Kalonzo has been missing from the political scene after he traveled to Germany last month.
Reports indicate that he accompanied his ailing wife for treatment.
Meanwhile, National Super Alliance (NASA) leaders have planned a grand reception for their two principals when they jet back to the country.
On Thursday, the Opposition team is set to conduct a rehearsal rally at Kamukunji grounds in preparation for the grand event scheduled for Friday.
"We welcome all Kenyans to this grand Thursday rally and the arrival party on Friday. All these are part of our continuing journey of ensuring electoral justice and putting an end to the evil culture of sham elections with pre-determined outcomes,” Siaya Senator James Orengo stated.
He, however, could not confirm whether the Wiper Leader would be present.