By Keith Idec

Sergey Kovalev will fight another southpaw in his next fight, this time an unbeaten American Olympian.

BoxingScene.com has learned that an agreement was reached Sunday for Kovalev to defend his WBO light heavyweight title against Marcus Browne. Their 12-round fight will be broadcast by HBO and will take place in The Theater at Madison Square Garden, the site of Kovalev’s last two fights.

The date for the Kovalev-Browne bout hasn’t been finalized. It could take place as early as June 23.

Whenever it happens, Browne (21-0, 16 KOs) has accepted by far the most challenging assignment of his five-year professional career. The Staten Island, New York, native has scored quick knockouts in back-to-back bouts, but those impressive victories came against fringe light heavyweight contender Sean Monaghan (29-1, 17 KOs) and Francy Ntetu (17-2, 4 KOs).

The 27-year-old Browne beat Ntetu by first-round technical knockout January 20 at Barclays Center in Brooklyn.

In Kovalev (32-2-1, 28 KOs), the tall, strong southpaw will encounter an elite light heavyweight champion who has lost only to former pound-for-pound king Andre Ward (32-0, 16 KOs). Russia’s Kovalev, who’ll turn 35 on April 2, has begun rebuilding his reputation since suffering a controversial eighth-round technical knockout loss to Ward in their light heavyweight championship rematch June 17 in Las Vegas.

He won back the WBO 175-pound championship he lost to Ward in their first fight by knocking out Ukraine’s Vyacheslav Shabranskyy (19-2, 16 KOs) on November 25 at The Theater. Kovalev’s second-round stoppage of Shabranskyy enabled him to take back the title Ward vacated when he retired in September.

Kovalev returned to The Theater to stop fellow Russian Igor Mikhalkin (21-2, 9 KOs) in the seventh round March 3. There was talk of Kovalev fighting WBA champ Dmitry Bivol (13-0, 11 KOs), who stopped Sullivan Barrera (21-2, 14 KOs) in the 12th round on the Kovalev-Mikhalkin undercard, in his next bout.

If they both continue winning, a Kovalev-Bivol bout probably won’t take place until later this year. That opened up this opportunity for Browne, who turned down chances to face Kovalev on November 25 and March 3 because he wasn’t offered an acceptable purse.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.