Bongi has a 'big engine'
Mbonambi, who has been part of the matchday squad in seven of South Africa's 11 Tests this year, will make his first Bok start of 2017 against Italy on Saturday.
To say he has been used sparingly would be stating the obvious.
The Western Province hooker has played just 80 minutes, compared to Bok first-choice hooker Malcolm Marx's 800 minutes.
Against France in June Mbonambi played just 36 minutes, compared to the 204 minutes of Marx. In the Rugby Championship, he played just 34 minutes, compared to the 447 of Marx. And on the year-end tour, he has played just 10 minutes, when Marx was injured last week against France. The remaining 150 tour minutes belonged to Marx.
Marx will not feature this week, as a result of the shoulder injury he suffered in Paris.
The Bok coach, Coetzee, believes Mbonambi "deserves a start" and that he will bring his own brand and value to the game.
"He played really well at Currie Cup level, especially in the semifinal and Final," the coach said.
"He is [also] training well and looking good at training."
Coetzee admitted there will be questions about Mbonambi's merits.
"I rate Bongi highly as a player," he said, adding: "He is a good player and fits in well with our plan.
"Bongi comes with his own strengths. His defensive ability is unbelievably good."
Like any hooker, it is his primary roles, such as set pieces, that are important.
"He has to make sure we have an accurately functioning line-out. At training this week Bongi has been throwing in superbly and we have good line-out options.
"He is a great scrummager. We have seen [how] the Stormers front row scrum with him and Wilco Louw. From a scrumming perspective, don't just look at the props, look at what the hooker does in tandem with Wilco [Louw].
"In general play, he may not be renowned as a good ball carrier, but he can take the ball up if he needs to.
"His biggest asset for us is to play towards the ball.
"His strength is that he has an engine. He doesn't stop playing, he is all over.
"You will see him in the kick-chase, you will see him make double contributions on defence."