A head injury has kept Brown out since January while Fagerson has made just one substitute appearance for Warriors since injuring his foot last month.
Glasgow assistant coach Kenny Murray said: "Fraser didn't play last week but has trained fully this week. Hopefully he should be in contention for Ulster.
"Zander has been running about and looks pretty good at training so he will also be in contention for this weekend.
"He did well last weekend in his first game back against Munster and has had two good days' training this week so all is looking good."