Fresh from his record-breaking feat last week at the British Rowing Indoor Championships, Surbiton's Mohamed Sbihi now faces an unusually tough challenge tomorrow.
He will race in a single scull at the Winter Assessment designed to whittle down the GB Rowing Team squad as Rio 2016 comes closer. The last-minute switch for the defending men's pair champion comes because his partner, Alex Gregory, is ill.
It means that Sbihi will need to race alone in an entirely different discipline to prove his mettle. This new test comes exactly a week since he broke Sir Matt Pinsent's 11 year old 2k indoor rowing record a week ago at the Olympic velodrome.
Olympic Champions Pete Reed, from Gloucestershire, and Yorkshire's Andrew T Hodge, coming back after a long lay-off, are still amongst those racing two consecutive time trials followed by side-by-side finals in the open men's pair event at the national training centre.
Earlier Sbihi had talked of the emotion involved for all the squad members this weekend: "It is another important step towards Rio. The trials process is never fun - you are racing your teammates and friends - but it is important in making our team as strong as we can be for the summer. Of course there is tension, every day that passes is moving closer and closer to Rio and everyone wants to get the best result possible to strengthen their chance of going to Rio."
In the open men's single scull event which Sbihi now joins, Sam Townsend, Jonny Walton and John Collins who took the top three spots in the autumn over a 5km distance, will be in the hunt for podium places. Charles Cousins, from Cambridgeshire, winner of last season's final set of trials, is training fully but is not "quite ready" to race yet according to the coaching team.
Coleraine's Alan Campbell is returning to the kind of form that saw him win a 2012 bronze and will be amongst the contenders to win on Saturday. Graeme Thomas, 2013 and 2014 World quad medallist will also be in action after missing the autumn trials.
There will also be trials in the open women's single and the two lightwieght disciplines.
Alongside trials for the Rio squad, a number of rowers will be seeking to impress the selectors and coaches in time for next year's World U23 Championships in Rotterdam.
The nation's top para-rowers will be put through their paces on Saturday in a closed test on indoor rowing machines (ergos).