Schultz has taken a more active role in politics in recent years. However, in an exclusive interview with CNBC earlier Tuesday, he declined to specifically talk about whether he would challenge President Donald Trump in the 2020 election.
"There's a lot of things I can do as a private citizen other than run for the presidency of the United States," Schultz said. "Let's just see what happens."
However, he still opined on a number of political issues and even took a few shots at Democrats, saying many leaders in the party were veering too far left.
Despite the fact that Schultz, if he ran as a Democrat, would be facing left-leaning candidates if he decided to run, Rendell still thinks he has a chance in the Democratic primary if the field is made up of 11 or 12 people.
"In an 11-person field, maybe 26 percent wins the primary. Who's to say he couldn't slice off 25 percent of moderates?" Rendell said.
He said what Schultz needs to do is position himself as a problem-solver, the former governor said.
"He would have to look at the camera when he announces and say, 'I'm going to tell you the truth I'm not going to tell you what you want to hear. … We're going to solve some of the problems facing American in a bipartisan, nonideological fashion. We're going to make tough decisions,'" Rendell said.
However, Schultz still has a lot of work ahead of him if he decides to toss his hat into the ring.
"I'm not saying he's there yet," Rendell said. "He's got the herculean task of convincing people to vote against their short-term interest and vote for their long-term interest. It hasn't been done in a while, but John McCain almost did it in 2000."
The other option is running as an independent, GOP strategist Sara Fagen told "Power Lunch" on Tuesday.
"The country is ripe for an independent candidacy," said Fagen, who was a senior aide to President George W. Bush.
The number of people registering as independents is on the rise and has hit a 70-year high, noted Fagen, who is a CNBC contributor.
Schultz served two stints as CEO of Starbucks and will step down as executive chairman on June 26. He'll then become chairman emeritus.