McClenaghan tweeted his enthusiasm this week.
"London time! Fizz levels are high to get stuck into the Champions Trophy now! @BLACKCAPS see you boys soon!"
The only concern will be his bowling at the death. He played one of Mumbai's last four games.
With Adam Milne also returning from injury, and Trent Boult and McClenaghan's Mumbai teammate Tim Southee playing six and three IPL games respectively, the pace bowling balance will be intriguing if New Zealand play spinners Mitchell Santner and Jeetan Patel.
McClenaghan's ODI record of 82 wickets in 48 matches at an average of 28.2, strike rate of 28 and economy rate of 5.94 is strong. It is enhanced when filtered down to his 10 ODIs in England where he has 23 wickets at 24.65, taking a wicket every 23 balls and conceding 6.51 runs per over.
Staying with the IPL, Williamson had limited opportunities - seven - for the Sunrisers Hyderabad, having been relegated behind openers David Warner and Shikhar Dhawan for much of the tournament.
Some will consider that wasting the talent of the world's third-ranked T20 batsman. Conversely, the break from sustained top level cricket might benefit him for the Champions Trophy.
He endured an intense maiden home summer as New Zealand captain, carrying the team at times. The punctuated game time might have offered a chance to relax.
Williamson scored 256 runs at 42.66 with a strike rate of 151 in the competition. That's the 12th best for any batsmen who played seven or more 2017 IPL innings, and higher than Martin Guptill (150) and Brendon McCullum (147).
Elsewhere off-spinner Jeetan Patel has found consistency on English wickets.
His Warwickshire side have lost six of their eight Royal London One-Day Cup matches to be last in the North Group, but Patel has taken their equal-most wickets (10) at the lowest economy rate (5.12). He averages 35.30 with a strike rate of 41.
Patel is preparing for the Black Caps' fourth and final ODI of the series, against Bangladesh tomorrow night in Dublin.