Imran Tahir is 36 years old. He has been an international cricketer for four of those years, and a professional one for 19. He has played for more teams and in more leagues than most people follow, and is currently ranked fifth in the world on the ICC's ODI bowling rankings. What more could he possibly want? His Test spot back, of course.

"I'm still challenging myself with that. When I go to bed after playing a Test match, I want to feel that I gave 100%. If not, I'll feel guilty and won't be able to sleep and probably will need sleeping tablets. But I know that in my heart I never did that," Tahir said.

"Whatever I did, I did it for South Africa. This is a dream I've had since I was 10. If I mistakenly drop my cap, I pick it up and kiss it. This is the biggest thing in my life. I have a lot of respect whatever format I play. I haven't developed as I should have in Test cricket, but I can work hard on that and that's what I've been doing."

Tahir made his Test debut in the same game as Vernon Philander and played the bulk of his Tests while South Africa's strategy was centered on their three-pronged pace attack. He often found himself bowling on surfaces totally unsuited to spinners and came into the attack once most of the damage was done. The strategy made it difficult for Tahir, as an attacking bowler to have an impact. His aggressive nature and myriad variations made it difficult for him to control the game. He lost his place to Robin Peterson, got it back briefly, and then lost it again.

Tahir last played a Test over Boxing Day last year against West Indies. He was recalled after being dropped for the one-off Test against Zimbabwe and then recalled for the opening Test against West Indies in Centurion. He was dropped again immediately after that match to seemingly end a Test career that had underwhelmed. He has since been overtaken by Simon Harmer and Dane Piedt in the longest format, but believes he could still find his way back, especially knowing there are also promising spinners putting up their hands in shorter formats.

Tahir was rested from the recent T20s in Bangladesh and against New Zealand, even though he is "not one of those guys who wants to take a long rest," and can see there is a succession plan being put in place. "There are lot of good youngsters coming up and it's good for them to get an opportunity. That's great for South African cricket, but the other side of it is that I don't want to lose my spot. That keeps me going. I want someone to be there to challenge me," Tahir said.

Eddie Leie has emerged as the most likely candidate to partner with Tahir at next year's World T20, and possibly even take over from him in the future. Although Tahir is not quite ready to roll off into retirement yet, he is willing to take Leie, his former franchise team-mate at Lions, under his wing.

"He's [Leie] a really good, talented guy. It was nice that he had an opportunity. I wish I had that when I was his age. He's a good, strong character and he wants to do well for South Africa. That makes him a good bowler. He's got all the variations, but probably he needs to learn a bit more about the game," Tahir said. "Wherever I could, I helped him. Actually, I did share all my secrets with him. What god has written for me, no one's going to take it away. I just want to pass it on."

While Tahir teaches Leie what he knows, he remains the go-to man in shorter formats. AB de Villiers described Tahir as a "master of the middle overs," who knows "how to change momentum, speed the game up and then slow it down again."

Words like that keep Tahir motivated as he aims to stretch out his career as long as he can. "That pumps my heart. Every time I see that I want to do well. I've been playing cricket for quite a long time all over the world and all the situations I have been in have given me confidence. I love challenges. I want to be the guy the captain can trust. I take my job very sincerely."