Buboy Fernandez, Nonito Donaire Sr, and the rest of Pacquiao’s backroom squad were unawares as Pacquiao visited a doctor for the procedure.
“When we were ECG, it seemed like someone saw the ECG’s result in a problem, so the doctor just made sure that there was no problem, so I was undergoing an angiogram,” Pacquiao told the Filipino press.
“They looked, no problem.
“My teams did not know that I was undergoing surgery,” he added.
Pacquiao went on to score his greatest victory of recent memory when stopping Matthysse for the WBA welterweight title in Malaysia, opening up the possibility of massive fights with Vasyl Lomachenko or Amir Khan down the line.
At 39, Pacquiao still looks in tremendous shape, although needs to be matched carefully in order to prolong his outstanding career.
Khan has already made his interest in facing Pacquiao known, but needs to come through Samuel Vargas in September in order to open talks on a potential December clash.
The pair used to train together under Freddie Roach and were linked to facing each other in 2014 before Pacquiao eventually agreed to fight Floyd Mayweather the following year.
“Manny looked good, he boxed well,” Khan told Elie Seckbach of ES News in the gym recently. “It was a great performance and he looked very sharp.
“I think it’s a good time for me to fight him as we are both coming off good wins.
“I have a fight coming up against Samuel Vargas on September 8th, but maybe at the end of the year or next year, it could be an amazing fight with Pacquiao.
“I don’t know what his contractual deal is like with Bob Arum but Bob’s a friend of mine,” he added.