Former India and Mumbai opener Sudhir Naik, who mentored Zaheer Khan in the early part of his career, has praised the bowler's achievements and said he is proud Zaheer had played 92 Tests for India. Zaheer announced his international retirement on Thursday, and Naik said that the bowler had accomplished "much more than what I thought he would" over the course of a 15-year career.

"When I look back, when I first saw him as a teenager after his father got him down to Mumbai from Shrirampur [a village in Ahmednagar district in Maharashtra], he has achieved much more than what I thought he would," Naik told ESPNcricinfo. "He has emerged as India's best pace bowler since Kapil Dev and it has fully reflected in his impressive numbers during his career."

Naik said that Zaheer had taken the decision to retire after realising that he could not perform at his best consistently at the international level with a hurt shoulder.

"He called me last night and told me he will make it official today," Naik said. "He feels with a hurt shoulder he cannot bowl at his best at international level consistently, so he has decided to call it a day.

"He knows that the lethal yorker that had emerged as a trademark delivery for him will not be effective in his international career [anymore] and there is no way he will want to stretch himself when he is not at his best."

Describing Zaheer as "a late bloomer", Naik said that the bowler's solid grounding in academics also made him a quick learner. Naik said that the first time he met Zaheer, he was convinced the bowler would go on to play for India and stated that 92 Tests was a lot more than Naik had expected from the bowler.

"He was one of the quickest learners as a youngster. Having sound academic background did help," Naik said. "He would take just one briefing to learn the nuances of every weapon required for a fast bowler.

"For instance, I remember having told him the dynamics of reverse-swing - the positioning of shiny and non-shiny sides. And being a good student of physics, after just one briefing, he started bowling it perfectly in the nets.

"I was convinced the first time I saw him that he would definitely play for India. But considering that he was a late bloomer, I thought he would end up playing around 50 to 60 Tests. By playing 92, he has proven me wrong and I am so delighted for it."

Naik rued the fact that Zaheer missed the chance to play 100 Tests for India. In the later part of his career, Zaheer was plagued by injuries, including one to his bowling arm. Once he was dropped from the Test side following the home series in England in December 2012, Zaheer played only four more Tests - two each in 2013 and 2014.

"Three years ago, when he had crossed the 90-Test mark, we had planned how he will celebrate the century," Naik said. "Once a batsman enters into the 90s, it is natural that he would want to get that hundred. Even though Zaheer was a bowler, the same principle applied to him when it came to Test camps.

"According to our calculation, he would have made the century in 2013 itself. But then came a major injury and even after he recovered from it, he suffered another shoulder injury. It's not that he cannot bowl any longer. But he knows that he cannot bowl with that zip. He can bowl at around 125-128kph, but that is not good enough to perform for India.

"If only he would have marked a century of Test caps, it would have been a fitting farewell to a glorious career. It was not to be. I am sure Zaheer will do a great job in moulding young bowlers and I wish him the best."

Amol Karhadkar is a correspondent at ESPNcricinfo