Bellamy said the Warriors had been badly affected in the pre-season by their heavy representation in the World Cup.
"I've watched their last few games pretty closely and you can see there's some signs that they're starting to play well.
"They were unlucky against the Bulldogs and put up a real good performance against St George last week so they're starting to get into their best form."
The Storm have made one forced change to the starting side that lost to Canberra with five-eighth Ben Roberts sidelined for up to six weeks with a knee injury.
Ben Hampton, who started the season in the No6 jersey, will again take over the playmaker role.
The Storm won the 2013 Anzac Day match 28-18 but the Warriors hit back in their round 20 match 30-22. The Warriors' total of 14 wins against the Storm is the second most of any NRL side. Six of them have been on Melbourne's home ground.