A lot can change on cricket tours. Tarun Nethula went away to the West Indies and India as the future of New Zealand spin bowling; a 29-year-old leg-break bowler with a national contract who might pressure Daniel Vettori in the latter part of his career.
Nethula returned home having lost his cricketing mojo; a bowler bereft of guile and confidence who was struggling to land, let alone spin the ball.
There is no single reason for his demise.
Leg spin bowling is arguably the most difficult art of the game to master. So much can go right when the ball pitches and rips the rough on a good length; far more can go wrong in the process getting there.
Shane Warne is a perfect case study. Midway through his third test in Sri Lanka he had one wicket and his average was 335. Then, with Sri Lanka needing 31 runs to win chasing 181, Warne took three wickets in 13 balls without conceding a run to mop up the innings and the match. His career rarely dipped again.
Since playing in the Caribbean in July, Nethula has been incapable of matching the form which got him selected for New Zealand last summer. He took 26 wickets at 30.46 in the Plunket Shield and bowled New Zealand A to a limited overs win over India A at Lincoln last month with figures of three for 46 from 10 overs. However, in three first-class, two one-day internationals and two list A matches since March he has taken just 10 wickets at an average of 58. To make matters worse, he developed a bad no-ball problem in his last match, bowling 12 against India A.
Nethula's not alone as a New Zealand leg spinner scrapped after minimal use. Think of Greg Loveridge and Brooke Walker in recent memory. National coach Mike Hesson admits they were not in a position to persevere with him in his current state.
"He lost a bit of form and wasn't bowling so well in India. Being on tour and not playing a lot makes for an awkward situation. Tarun needed to try to get some skills back in the A series against India. He also needs the support of the Central Districts management team."
In the absence of the injured Vettori, Nethula's yips in India meant New Zealand couldn't play a preferred two-prong spin attack. It put extra pressure on Jeetan Patel. He mustered one of his better series to alleviate some of the punishment the side took in the 2-0 series loss.
Hesson expects two spinners to be required in the Sri Lanka tests at Galle and Colombo. Cue Todd Astle. With Vettori again out, this time recovering from an Achilles injury, Astle's batting could be an asset at No 8 in the order. The 26-year-old has a first-class hundred and opened for Canterbury in the early part of his provincial career. Add that to his 68 wickets at 33.31 over the last two seasons and his skill set is more desirable than Nethula's.
"Todd's a good character who trains hard and has taken plenty of his wickets in the second innings of matches," Hesson says. "He's got the confidence to chuck the ball up and beat players in the air. His record of 55 [first-class] games with 127 wickets at 34.79 is pretty good by New Zealand spinning standards. He's excellent in the field but hasn't fulfilled his potential with the bat.
"When playing two spinners, you're committed in some way to one guy who can at least bat a bit. Todd's that man because we can't expect too many runs out of Jeetan.
"Todd lives and breathes the game. He's passionate and we'd be more inclined to use him on this tour as opposed to South Africa or England. Dan will more than likely be back by then and pace bowlers might also be better options."