"You have to say that the players have changed it,'' he said. "They've done that themselves with a bit of encouragement, and it's a big plus.
"We're going out to win games and, despite being extremely stressed with the physical aspects of the game, I thought they really gave everything they had to win that game.''
Defeat instead left the Phoenix in ninth, three points outside the playoff positions, with last night's trip to Auckland bringing a chance to close the gap on the fifth-placed Adelaide.
The Phoenix have failed to earn a win against Adelaide since February 2012, although the two teams are yet to meet this season. Adelaide will come into the contest after a 2-2 draw at home to last-placed Melbourne Heart, and the South Australians may be ripe for the picking.
If the Phoenix can repeat the result from their last trip to Eden Park - a 1-0 win over Perth last season - it could kick off another winning run, with their following two matches coming against sides in the bottom three.
Wellington will be boosted by the return of Carlos Hernandez and Kenny Cunningham after the pair missed the Brisbane match through international duty. Both men started in Costa Rica's 4-0 loss to Chile and both should do likewise against Adelaide, with Merrick conceding his side were lacking the service the duo typically provide.
"There's no doubt we missed Kenny and Carlos,'' he said. "There was no service coming forward for the strikers towards the end of the second half.''
Merrick thought one man who was especially let down in that regard was Roy Krishna, with the Fijian frontman struggling to make an impact when summoned from the bench.
Krishna, who has made two brief appearances for the Phoenix since signing with the club earlier this month, should get another chance in the city where he made his name with Waitakere United.
"He was making little runs in behind [against Brisbane],'' Merrick said. "Although he struggled a little bit, there were a few flashes that showed me his ability.''