The Saints were out-run and out-classed on Saturday night, losing to the ladder-leading Bombers by 37 points at Etihad Stadium and slumping to 1-3 for the season.
Watters said Arryn Siposs and Tom Lee, who were late withdrawals against Essendon, would be considered for the historic Anzac Day clash, as well as ruckman Tom Hickey.
He said the Saints, who fly to New Zealand on Tuesday and have a five-day break, would travel with a squad of up to 26 players.
"We probably looked at both these games as one campaign," Watters said on Saturday night.
"There are some players that didn't play tonight that certainly will come into consideration.
"Given the length of break, I think you'd be crazy to select an identical side.
"We will be bringing some fresher players in."
St Kilda's undersized backline was again an issue on Saturday night, with James Gwilt (knee) and Sean Dempster (hand) still sidelined.
Tom Simpkin, Sam Fisher and Rhys Stanley matched up on the Bombers' tall forwards, who were influential in the air.
"Twenty-two contested marks to nine, that's not great reading," Watters said.
"Their size going inside forward 50 was a challenge for us tonight.
"Their key forwards kicked nine goals – (Scott) Gumbleton, (Tom) Bellchambers and (Michael) Hurley – so we were probably stretched there."
Watters said he would continue to use Stanley as a key defender, while Tom Simpkin would come into the back six.
His message to the players post-match was that contested ball was an issue and opportunities need to be taken after costly misses leading into half-time that could have stopped the Bombers' run.
On the challenge of playing the premiers in New Zealand after a shortened break, he said: "It's a tough competition and you need to get back up. Our players will do that."
Nathan Schmook is a reporter for AFL Media. Follow him on Twitter: @AFL_Nathan
