The pair look set to fight later this year as the Irishman continues his route away from MMA.
Both McGregor and Pacquiao are managed by Paradigm's Audie Attar, who is determined to host a super-fight in 2021.
Speaking about the potential clash, Foreman told the Daily Star: "I think if he has a fight with Pacquiao he can actually beat him - good rules, over 10 rounds, McGregor can beat him.
"He's already adjusted to boxing, he's not going to do good in MMA anymore.
"Pacquiao is very good as a matter of fact but McGregor can beat him."
A bout was rumoured to be in the works last year, but McGregor instead decided to face Dustin Poirier at UFC 257.
'The Notorious' was beaten via TKO in just the second round to leave his UFC comeback in ruins.
He could now turn to boxing to get his career back on track.
McGregor made his debut against Floyd 'Money' Mayweather in August 2017.
He lost via TKO in the tenth round as Mayweather took his undefeated record to an incredible 50-0.
The financial implications from the fight were massive. The pair each took home a huge purse, with McGregor's thought to be in the region of $85million.
In comparison, the 32-year-old earned around $5million for his UFC bout against Poirier.
That means he will likely focus on a career-ending high by taking on Pacquiao before hanging up his gloves.