HBO is taking in stride the loss of two of its marquee boxers -- unified junior welterweight champion Terence Crawford and junior lightweight titlist Vasyl Lomachenko, two of the best pound-for-pound fighters in the world -- to ESPN.

HBO has been involved in all but one of Lomachenko's nine professional fights and it has been involved in 11 of Crawford's past 12 bouts. The network has put considerable time and resources into advancing both of their careers.

However, promoter Top Rank, seeking a bigger platform than premium cable network HBO, announced on Thursday night that their next bouts would be on ESPN as part of a longer-term deal it is finalizing with the network. It will leave HBO without access to Top Rank's loaded stable. Top Rank has been one of HBO's main fight suppliers for decades.

"Our fight lineup includes an array of 50-50 competitive fights, culminating with the best fight of 2017 in Canelo Alvarez versus Gennady Golovkin on Sept. 16," HBO Sports executive vice president Peter Nelson told ESPN on Friday. "We, however, cannot show every fight, though we remain fans of Terence and Vasyl, and proud of what we did for their careers together with Top Rank. We wish them the best."

HBO still works with Golden Boy Promotions, K2 Promotions, Roc Nation Sports and Main Events, and has fighters such as Golovkin, Alvarez, Andre Ward, Wladimir Klitschko, Roman Gonzalez and Sergey Kovalev as part of its roster.

Lomachenko (8-1, 6 KOs) will defend his 130-pound belt against former featherweight world title challenger Miguel Marriaga (25-2, 21 KOs) on Aug. 5 at the Microsoft Theater in Los Angeles, and Crawford (31-0, 22 KOs) will face fellow two-belt world titleholder Julius Indongo (22-0, 11 KOs) at Pinnacle Bank Arena in Lincoln, Nebraska, a short drive from Crawford's hometown of Omaha, in an effort to unify all four titles in the division. It will be only the second four-belt title unification fight in boxing history; the other was Bernard Hopkins' knockout of Oscar De La Hoya to unify the four middleweight titles in 2004.

Top Rank was able to finalize the deal with ESPN for the Lomachenko and Crawford cards after HBO, which had the right to match the ESPN offer, allowed its window to match close on Thursday without making one.

Top Rank's biggest star, welterweight world titleholder Manny Pacquiao (59-6-2, 38 KOs), also has left HBO after years as a cornerstone contract pay-per-view fighter. He will make his ESPN debut in a title defense against Jeff Horn (16-0-1, 11 KOs) at Suncorp Stadium in Brisbane, Australia, on Saturday night (ESPN and ESPN Deportes, 9 p.m. ET) after Top Rank turned down an offer from HBO to put him on the network this weekend.