Matters grew worse on Saturday when their Urayasu D-Rocks side was outclassed 62-19 by Shizuoka Blue Revs.
Having managed just eight appearances across the past two years due to injury, Folau has already equalled the two games he played last year and has made some major run metres but the 35-year-old's presence has failed to lift the newly-promoted side.
D-Rocks have shipped 93 points on the first two weekends of the competition.
While Folau and Kerevi have suffered an 0-2 start to the fourth edition of Japan Rugby League One, so too has Verblitz NRL recruit Joseph Manu.
The former Roosters centre, who was a try-scorer on debut last week, came from the bench on Saturday as the Steve Hansen-coached outfit lost 21-17 to Mie Heat.
A week after beating Verblitz with an injury time drop goal, ex-Wallaby flyhalf Bernard Foley missed the chance to do the same in Saitama, with his late penalty goal attempt off target as Spears Funabashi Tokyo Bay lost 26-24 to the Robbie Deans-coached Wild Knights.
It was the 16th time in their last 17 meetings the Spears have come up short against the Wild Knights.
Kobe Steelers beat Yokohama Eagles 36-18 on Sunday to secure a first win of the season for Deans's fellow ex-Wallaby coach Dave Rennie.
Brave Lupus Tokyo bagged the second win of their title defence by flattening Sagamihara Dynaboars 61-8 on a crazy afternoon in which the ladder leaders rattled on seven tries in 20 minutes.
Elsewhere, the Australian trio of Paddy Ryan, Liam Gill and Isaac Lucas enjoyed their first win of the season after Black Rams Tokyo beat Tokyo Sungoliath 33-32 for a first win in 17 attempts against their rivals.
Last season, Sungoliath had beaten Black Rams 62-0.
There were also smiles for ex-Wallaby halfback Nick Phipps, who experienced his first win captaining a side in Japan after Green Rockets Tokatsu snapped a six-game losing run by beating Kamaishi Seawaves 59-17 in Division Two.
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