By Edward Chaykovsky

WBO welterweight champion Manny Pacquiao has not had a knockout win since 2009, when he stopped Miguel Cotto in the twelfth round of their bout which took place at a catch-weight of 145-pounds.

Pacquiao, 38 years old, reached a deal to fight Khan (31-4, 19 KOs) in the coming months. Both sides are trying to finalize a date of May 20 in the United Arab Emirates.

For the last two years, Brook has been trying to get Khan in the ring. They were in serious talks earlier this year, but those negotiations fell apart after both sides were far apart on the money.

Once the fight with Khan fell out, Brook reached an agreement to make a mandatory defense against Errol Spence - which is also targeted for late May.

"I don't know about fighting Amir Khan and I don't really care any more," Brook told Nick Parkinson. "I'm not stopping anything on my side from happening and I've been willing to bend on matters like the purse split.

"If everything was transparent every boxing fan in the world would be behind me on this matter. But I've got Errol Spence on my mind right now but there's Keith Thurman and there are other big fights out there for me other than Khan. If my career does end and Khan isn't on my record I will be able to rest in peace knowing that I've tried everything I could to give the fans the fight they wanted to see."

Khan has been out of the ring since suffering a vicious sixth round knockout at the hands of Saul 'Canelo' Alvarez last May at the T-Mobile Arena in Las Vegas. For that contest, Khan had moved up to a catch-weight of 155-pounds.

Although Pacquiao is nearly 40 years old, Brook believes the veteran has more than enough left in the tank to knock Khan out.

"I still believe Manny Pacquiao will stop Khan," Brook said. "He's getting on a bit Manny but he's still good enough and there's enough energy in his legs and he will still beat Khan."