The TFC coach wants to put in a good effort against Liverpool on Saturday, but also sees the need to rest key players in a meaningless match that comes at a particularly gruelling time in the schedule.
"I think everybody knows we've had a very interesting month or so," Mariner said at a press conference Friday. "(But) I think we want to give a good show."
Toronto FC, which will meet Liverpool on a temporary sod pitch at Rogers Centre, has played 10 times since June 16 but Mariner says whatever team he fields will be ready.
"I don't think we want to let ourselves down," he said. "I know the players absolutely won't let themselves down."
A group of players who won't be putting on a show are the Liverpool stars who took part in the recent European Championships.
A press release on Wednesday stated that England internationals Steven Gerrard, Glen Johnson, Andy Carroll, Stuart Downing and Jordan Henderson would be in the squad travelling to Toronto.
But in a another statement released less than 24 hours before kickoff, organizers announced that "due to FIFA regulations surrounding mandatory vacation dates" following international tournaments, all players who took part in Euro 2012 would miss out on the trip to Canada.
Liverpool manager Brendan Rodgers, who took over the club for the fired Kenny Dalglish on June 1, bristled at the suggestion Canadian fans would be disappointed with his lineup.
"I think we have a lot of big players here, some of the core of the group that's going to be very very important to us and we have some stars of the future — young players," said the 39-year-old Rodgers. "Of course we have some players that aren't here but the reason they're not here is that they have to recover.
"I don't think it takes away from the players that we've got — top international players, players that are multi-skilled and players that will fight for the shirt."
Mariner is also planning to field a squad that will include players who have yet to see first-team action, as well as some members of TFC's youth system.
He adds the game should be viewed more as a chance to evaluate what Toronto has in the cupboard.
"This is an ideal opportunity for us to see what we've got. The game is the biggest teacher," he said. "Whether it's a scouting game or a training game or any game — the game's the best teacher. It's much better than training. You can learn so much about your players."
Toronto FC is 4-2-4 since Mariner took over for the fired Aron Winter after a dreadful 1-9-0 start, and the former England international is wary of a slip up in form against Liverpool.
"We just want to keep things going. We're not going to do anything different," said Mariner, whose team faces another critical league game at home against Houston on July 28. "We're just going to play our game and play our shape and our disciplined game and see what happens."
Toronto FC midfielder Terry Dunfield expects to take part in at least some of Saturday's match and says it's a chance for players to see how they stack up against top-level competition.
"It's a great opportunity for some of the younger guys to show what they can do, not just in a reserve game but in a full on first-team game with a big crowd," said the Canadian international. "We'll see what some the young guys are made of."
Toronto FC defender Richard Eckersley is from England and understands the importance of a game against a Premier League powerhouse.
"We're representing the MLS and it's huge for us," Eckersley said. "If we can put on a good show hopefully they'll have more respect for us."
Liverpool, which has won England's top division 18 times, will take on Italy's A.S. Roma at Boston's Fenway Park on Wednesday, before meeting Premier League rivals Tottenham on July 28 in Baltimore.
Organizers say all of the missing England internationals will be available to take part in those two games.
Liverpool comes to North America with renewed hope. The club has failed to contend in the Premier League of late and will miss out on the Champions League for a third straight campaign in 2012-13.
Dalglish, a Liverpool legend as a player, was fired after an eighth-place finish last season and replaced with Rodgers, who led Swansea City's promotion to the Premier League and oversaw the club's 11th-place finish in 2011-12.
Rodgers, who will be managing his first game with Liverpool on Saturday, say it's an honour to lead such a storied club.
"You always hope when you start coaching or playing that you could work at one of the biggest clubs in the world and at 39 years of age I've been pretty fortunate," he said. "It doesn't frighten me or daunt me, it inspires me and excites me. The history of the club is a real motivation for me."
Notes: Newly acquired forward Eric Hassli won't make it to Toronto in time for the friendly match. He was acquired in a trade with the Vancouver Whitecaps late Friday. ... Liverpool starting goalkeeper Pepe Reina (Spain) and striker Fabio Borini (Italy) also did not make the trip to Toronto. ... Liverpool strikers Craig Bellamy (Britain) and Luis Suarez (Uruguay) are scheduled to play for their respective countries at the London Olympics are not on the North American tour. ... Both Toronto FC and Liverpool practised on the Rogers Centre turf on Friday with the roof open. Rodgers said the temporary pitch laid over the concrete floor "isn't so good" but he added that he's confident it won't be an issue on Saturday.