Serrano has 30 days to make an appropriate decision. The last time the 34-year-old athlete boxed was in September, defeating Sarah Mahfud on points.
For the Puerto Rican, it was a return to the ring after defeating Katie Taylor in April. Their rematch is tentatively scheduled for the first half of the year, but due to the unification fight with Cruz, the date of the second fight with the Irishwoman may change.