Bradley Fewster and Lubo Satka, on loan from Middlesbrough and Newcastle United respectively, recently started four games on the spin over an 11-day spell.
That run saw York climb out of and then drop back into the relegation zone, although they are currently level on points with 22nd-placed Yeovil.
There are also doubts over Satka’s availability due to an ankle problem, but McNamara is considering the potential impact of burn-out.
He said: “We have got to make sure people are fresh enough to put in a shift and help the team be successful.
“Brad Fewster has played the last four games and I’ve got to think about whether we’re asking too much of the young players.”
York have a capable replacement for Fewster in Vadaine Oliver. The top scorer is likely to start after playing a cameo role against Northampton on Tuesday.
Oliver, who has bagged nine times this season, has fully recovered from a hip problem and tonsillitis.
McNamara is insistent that Oliver will not simply stroll back into the first-team. Players have returned during Oliver’s absence, providing him with greater competition than at any other point this campaign.
McNamara said: “I thought Vadaine did okay.
“He held the ball up better than he has in other games, but he has competition now with Brad Fewster scoring goals, Jake Hyde coming back in and Reece Thompson being around.
“I want them scoring and pushing each other, so they’re busting to take their chances in the team and keep their shirt. The same applies to the rest of the squad.”
The Minstermen were handed a boost yesterday after the club brought in Huddersfield Town defender William Boyle on loan until the end of the season.
The 20-year-old, who spent a month at Bootham Crescent earlier this season, could step straight into the breach to replace Satka against Luton.
McNamara was clearly happy to bring back a player that he worked with shortly after his appointment.
“I’m delighted to bring him back,” said McNamara. I thought he was excellent before. He was aggressive in the air and a very good talker for a young player.”
Last six: York City WLWWLL Luton Town WLDWLW
Referee: G Eltringham (County Durham)
Last time: York City 0 Luton Town 0; September 16, 2014; League Two.