McFadden made his competitive return in the 73rd minute of Motherwell's Clydesdale Bank Premier League match against Dundee United on Tuesday night, but despite some good touches and a couple of blocked shots he could not prevent a 1-0 defeat.
The 29-year-old had only made three substitute appearances for Sunderland previously this season, and McCall tried to temper expectations from the fans, directors and player himself after the game when he warned McFadden did not have a "magic wand".
But McCall is looking to find the balance between helping the former Everton and Birmingham forward regain his match fitness to boost his own attacking prospects, while rewarding the rest of his second-placed side for their form.
McCall, whose team face Ross County in Dingwall on Saturday, said: "I`m not saying he expected miracles for himself but he wants to show what he can do and get involved. It will maybe be a case of drip-feeding him at the beginning. He had 20 minutes the other night and we'll see what he gets on Saturday.
"But he has missed a lot of football. Fitness-wise and training-wise he is up to speed and certainly a lot better than he was in the summer, but match-sharpness and game-time he is certainly lacking.
"I think if we started him, we wouldn't get a full 90, but we have a lot of games coming up and parks are very heavy. We have just got to try to get him up to match speed and get him going. He is here to play football."
McFadden's signing was hailed by a Motherwell support to whom he has remained a hero since his move to Everton 10 years ago. But McCall is eager to stress that McFadden is at Fir Park as a team player.
The Motherwell boss said: "I don't think the squad needed a lift because we have done well this season, but obviously it's been a great lift for the supporters. They remember the Faddy of old.
"It's not the James McFadden show, he is part of a squad and he is part of a team and he is happy to be that. I'm sure once he gets up to speed he will be a great acquisition for us and it will do well for him and do well for Motherwell."