"We are sort of saying Tuesday is the cut-off, if somebody is not fit to fully train Tuesday - we get small enough windows as a group already - it would be pretty hard to include somebody post Tuesday.
"There are a number of guys who haven't trained yet but we are hopeful that Monday will turn a new leaf for us with the likes of Paul O'Connell, Sean O'Brien and Cian Healy. At the moment it is a bit of a wait and see," said Schmidt whose squad will train next Tuesday and Thursday before a light Captain's run on Friday.
Injuries to key players have overshadowed preparations for the upcoming clash with Samoa, but the Irish management team are confident of a return for the majority of them by early next week.
"(Healy and O'Brien) are both making really good progress. We would anticipate that there is a pretty good chance they will both be training Monday, at the latest Tuesday, but relatively confident with those two. Rory Best was back on the field training and he had a run-out on Tuesday," explained Schmidt.
"Tuesday will probably be the earliest for Paul which would be cutting it fine, but he is very much abreast of what we are doing. He has been out on the pitch for all the sessions. He is the sort of guy who does his homework pretty well.
"There is quiet optimism among the medical staff that Tuesday wouldn't be unrealistic for Paul if he can get out on the pitch on Monday and start doing some straight line, sub-maximum stuff."
The biggest concern perhaps is over Brian O'Driscoll, whose calf injury has limited him to just over 70 minutes of rugby so far this season.
But while that run-out for Leinster against Cardiff may have some cautious about his potential involvement in this November internationals, Schmidt said that he is confident O'Driscoll could start.
"The one thing I would say about Brian is that he is training really well. He is looking sharp. He is pretty comfortable on the pitch at the moment.
"I've no doubt a stealy mind can get over some fatigued lungs. At this stage I would be reasonably comfortable with Brian starting against Samoa if that is what we think is the best option."
That leaves Racing Metro 92 out-half Sexton, who flew back to Paris on Thursday night to prepare for his club's trip to Biarritz Olympique in the Top 14.
Should Sexton play against Biarritz, Schmidt said it was likely he would rest the triple Heineken Cup winner on Monday but wouldn't rule him out (of the opening GUINNESS Series game).
"I'm not sure what his involvement is (against Biarritz). It is one of those things that makes things pretty difficult because it is another uncontrollable.
"Having played 13 games in 12 weeks, you know a player will start to get a bit fatigued and you just become a little bit more vulnerable, a little less likely to avoid injury. So those are risks we will want to manage."
While Sexton joined up with his Ireland team-mates last Sunday, Schmidt admitted he looked fatigued. Sexton lined out 18 times for Leinster during the entire 2012/13 season, but has already made 13 appearances for his new French club.
"He just was pretty tired at the start of the week to be honest and he was pretty flat. I know Johnny at this stage and he is a pretty buoyant, bossy character in a really good sense because he gives great direction on the field.
"He was definitely a bit flat at the start of the week. He is bouncing back now but he is also taking a flight to Paris. That is unfortunately the way it is and if Johnny is run down next week and if he does play against Biarritz at the weekend, it is a great opportunity for Paddy (Jackson) or Ian (Madigan) to step up and try to make a mark."
The other point of discussion in the lead up to the GUINNESS Seres is the captaincy, with O'Driscoll, O'Connell, Sexton, Best, Jamie Heaslip and Peter O'Mahony all linked to the position.
But while it may be a talking point away from the squad, Schmidt is keeping his cards close to his chest, stating an announcement could be made next Tuesday or Thursday.
"To be honest, the captaincy is still a but of a mute point. I'm really enjoying the group. They are very much a very collective group. I know there is a lot said of guys coming from different provinces, (but) I think they mix pretty well.
"I think the guys who are showing leadership are mixed across the board. With the captaincy, it is really difficult to say because some of the candidates haven't trained yet - some of them are re-integrating into training, some of them have trained fully and it is trying to give a level playing field to potential candidates," he added.