She believes Reynolds American could pay up to $80 a share for Lorillard.
"I am still convinced that a deal is going to happen, and I think it's around the corner," said Herzog, who's considered one of the nation's top tobacco analysts. "A deal between Reynolds American and Lorillard makes a lot of sense. So, my conviction is quite high. I have about a 90 percent probability."
(Disclosure: Wells Fargo intends to seek or expects to receive compensation for investment banking services in the next three months from Altria Group, Reynolds and Lorillard, and the company also holds stock in Altria, Reynolds and Philip Morris.)
A merger between the two companies would also give them an edge in the-cigarette and vapor market. Lorillard is behind Blu e-cigs and Reynolds American owns VUSE.
"There would be increased scale, and that's ultimately the game here to drive margins in this new emerging category," added Herzog.
Shares of Lorillard, Herzog's top pick in the space, were up nearly 2 percent in after-hours trading. Reynolds American stock was flat.