The Sweden-based forward failed to pitch in Durban where the team was preparing for a crunch Africa Cup of Nations qualifier against Sudan at the weekend, citing fatigue as the reason.
“It’s not acceptable for a player to do this,” Mashaba told reporters after training on the outer fields of the Moses Mabhida Stadium on Tuesday.
“Unfortunately we received a letter from him via e-mail that says he played a lot of games and needed a rest. That is what is happening and we cannot do anything about it.”
However, Mashaba insisted he was not angry about the situation.
“I [don’t] get angry about these things,” he explained. “I’ve told myself that I need to afford myself a smile. But we need to follow up with the powers that be… maybe Fifa or Caf.
“What I want to hear is a person coming out clearly to say I’m not available. Then we know we need to do something.
“When I took up this position, I spoke about the question of patriotism, which is very important. But the country has too much of talent just to get disappointed about one person.”
Apart from Mahlangu, Wits midfielder Sibusiso Vilakazi has also withdrawn due to a toe injury.
Another concern for Bafana is a thigh injury to attacking midfielder, Thulani Serero, while striker Bongani Ndulula and midfielder Oupa Manyisa are carrying minor knocks.
Team doctor Thulani Ngwenya said Serero was the only real worry, but expected the Ajax Amsterdam star to be fit.
“It’s not a major injury or one that means he will be out of the team, it’s something minor and we are monitoring him,” he said. “We watched him through the training session and he did not have any pain. We will assess him again later.”
Meanwhile, Mashaba revealed that they were giving thought to bringing in some replacements to the squad.
“That will be decided later today,” he said. “We’re still sitting with the technical committee. We can’t just call up a player for the sake of it. We have to look other things that need to be managed, so we’ll have to decide on that.”
Another issue yet to be decided was the captaincy, following the death of Senzo Meyiwa last month.
Mashaba said that announcement will be made in due course.
“It hasn’t been giving me any headaches and it will definitely come around Thursday or Friday.”
He also felt the players had reacted well in Tuesday’s early session –the first since Meyiwa was shot dead by attackers in Vosloorus on October 26.
“The level of training this morning shows the boys have put that behind them,” Mashaba added.
South Africa play Sudan in the coastal city on Saturday, before facing Nigeria in Uyo next week.