#2 Stefan Edberg
The quality in Kyrgios’ game is there for everyone to see. That is an undisputed fact. What needs to change is his temperament and that is why Stefan Edberg could be an inspired choice. The 6-time Grand Slam-winning Swede who enjoyed a famous rivalry with Boris Becker during his days has also proven himself as a capable coach/mentor. Edberg famously helped Roger Federer rediscover his game in 2014 and the great man himself described Edberg as more of a mentor than a coach.
Which might exactly be what Kyrgios needs - a calming influence which can temper down his bad bits while accentuating his already considerable ability. Edberg worked a lot on the mindset of Roger Federer and a similar sort of touch might work wonders with the exceptionally gifted Kyrgios.