"I was feeling it by the end of the day because I had 10 rides," said Bosson.
"The fitness and stamina just isn't there and since I had Covid you can feel the energy drain when you really exert yourself.
"But I will be better for that day's riding and I am looking forward to Saturday."
With today seeing Mark Walker taking over as trainer for Te Akau as Jamie Richards prepares to move to Hong Kong, tomorrow's meeting presents Walker with the unique opportunity to train a Group 1 winner on his first major day back at the office.
Walker says he is loving being back in New Zealand and training at Matamata and agrees with Bosson that Dynastic is ready for tomorrow but both men warn stablemate Maven Belle could push him hard.
"I think the filly [Maven Belle] will be hard to beat," said Bosson.
"If she trails the leader, which could be the case from the ace, and the track is playing fair she has a real advantage."
Add in high-class fillies Wolverine and Lickety Split and the Sires' is the juvenile race of the season and one that could be decided by tempo and whether any rain arrives to make one section of the track more favourable six races into the meeting.
Walker and Bosson, the combo who will quickly become the punters' favourites even as Te Akau start to power down for the season, have a huge hand to play in tomorrow's other features at Awapuni and Bosson's soft hands will be crucial in trying to extend On The Bubbles out to 2000m in the Manawatū Classic.
He has looked tested at 1600m so the extra 400m could be a challenge and Bosson will need to switch him off for much of the race.
"It is a bit of an unknown the 2000m but he has a big class advantage on most of his rivals."
The main danger looks to be Pinarello, dropping back from the 2400m of the NZ Derby, and if the Classic is run hard he could sweep over the top of On The Bubbles.
Bosson said it was his choice to ride Brando rather than Prise De Fer in tomorrow's Flying Stakes, even though Brando had barrier 13.
He will also partner Tiptronic in the Awapuni Gold Cup and with barrier two he should be handy and hard to catch even with the 59kg topweight.