It was announced during the Marvel panel at San Diego Comic Con that Laurence Fishburne has been cast as Bill Foster, AKA Goliath.
It was reported that the film was looking to cast an African-American male actor in his late 50 or 60s for the role of a scientist. It was then reported that the role was Bill Foster, a role that Fishburne grabbed.
Bill Foster was the second Giant-Man, as well as the fourth and most popular Goliath. He has powers very similar to the ones that Hank Pym utilized when he held the mantle of Goliath. He is also a Biochemist and worked for Tony Stark at one point.
Foster has a very rich comic history and strong ties to Hank Pym. Those ties are something that would likely be touched upon in the film, especially since the casting call is looking for a male actor closer in age to Pym than Scott Lang.
Ant-Man and the Wasp hits theaters in 2018