The national team face Wales and Serbia on March 22 and 26 and McCall – as a member of Scotland manager Gordon Strachan's new backroom team – will have unique insight into McFadden's readiness to play.
The forward has already said he hoped to do enough in the next five games for Motherwell to make himself a contender for a Scotland recall for the first time in two-and- a-half years. For McCall, though, the priority is to ease McFadden seamlessly into a team which is sitting second in the Clydesdale Bank Premier League, while also nursing the 29-year-old back to full match fitness after almost two years out because of a serious knee injury. With that in mind those March days would seem to be far too soon.
"It's too early to say," said McCall, who may use McFadden as a substitute at Ross County today because of concerns about the playing surface at the Global Energy Stadium. "James has missed a lot of football in the last two years so I think primarily he's focused on getting game time. If it was to go swimmingly well and he got a lot of game time and plays well, then we'd have to wait and see. I haven't spoken to Gordon [Strachan] since James signed.
"I remember watching Scotland when James was at his peak. When we had games that were going to be tight you would always look for who could do something a little bit different and produce some magic; a maverick, if you like. James was always one.
"I have seen flashes of that magic from him in training but that's different from the rigours of 11 v 11, high-tempo football. We were pleased to get him on the other night for 20 minutes [against Dundee United] but it might be a case where we have to drip-feed him into games at times. I look at the park at Dingwall at the moment and it's probably not ideally suited. That's not a criticism, it's just a fact that we have to consider that it's maybe not in a great state for free-flowing football where people can dribble with the ball."
McCall was wrong-footed by McFadden's availability and had not planned to add to what has been a successful team. "James came right out of the blue for me and I was happy with what I had. I still had lads on the bench who were pushing to get a go," he said.
"So when James came training it wasn't with a view to signing him. I was actually away with Scotland when I got a call asking if it was alright for him to come and I said 'of course'. But there was never any thought in my mind that he was coming in to be part of the team so it took me a little bit by surprise when he came knocking on the door on Monday afternoon. We just talked football and that was good."
Having a player like McFadden in reserve may prove useful if Motherwell prove unable to unpick a County defence which has not conceded in three of the last four matches. That has been down to a tactical switch which has allowed the Highland side to rely on their more robust traits rather than trying to force a more inventive style of play which did not always seem to fit.
"Probably midway through the season we went to try to win a few matches and opened up a bit, and it didn't really suit us," said Derek Adams, the County manager. "We have got back to what we are good at – being solid, playing on the counter-attack and keeping good possession in the middle of the park. We looked at it and looked at the players we have got, and they are suited to a system."