WBO welterweight champion Jeff Horn (17-0-1, 11 KOs) is already setting his sights on other potential targets in the welterweight division.
Last month, Horn stunned the boxing world when he pulled off a twelve round unanimous decision over Manny Pacquiao to capture the WBO crown before a crowd of 51,000 at the Suncorp Stadium in Brisbane, Australia.
There is an immediate rematch clause in the contract, but Pacquiao has yet to exercise that option.
As the weeks continue to pass by, it's becoming a real possibility that the 38 year-old Pacquiao retires from the sport or decides to go in another direction by fighting someone else.
Horn took to social media and issued a challenge to IBF welterweight champion Errol Spence (22-0, 19 KOs) - and used Spence's 'man down' catchphrase.
"Lets fight, let's unify, there will be a man down," Horn stated.
Spence captured the IBF belt back in May, when he traveled over to Sheffield and stopped Kell Brook in eleven rounds. He is expected to make a voluntary defense of the title on a date in October or November, against an opponent to be announced.
At one point last year, Horn and Spence were both in line to face each other in an IBF final eliminator. Horn went in another direction, which saw the sanctioning body offer the open opportunity to Leonard Bundu - who Spence brutally knocked out to secure his shot at Brook.
If Pacquiao does retire, it's very unlikely that Top Rank would place Horn in the ring with Spence. Top Rank is going to keep it in-house. As a result of the Pacquiao fight, they have a few fight options on Horn, and several Top Rank officials have already named Terence Crawford as a Plan B opponent for the Australian star. Crawford would first have to win on August 19, when he faces Julius Indongo in a high stakes clash for the IBF, IBO, WBA, WBC, WBO junior welterweight belts.