The midfielder hurt his calf in the first quarter of their opening-round match and has missed the three games since.
The Lions were 0-2 but beat St Kilda on Saturday and then, battling further injuries, trounced Collingwood 17.17 (119) to 10.5 (65) at the Gabba on Thursday.
Co-captain Harris Andrews will return from suspension against North Melbourne on Saturday in Adelaide's Gather Round, while defender Noah Answerth should also be available after suffering a concussion last week.
But Fagan said McCluggage, the third-quickest player in AFL/VFL history to play 200 games, could miss another week.
"It's just going slow, but he turned the corner this week," Fagan said.Â
"He's more ready to play. It'll be line-ball with him.
"One of the quickest men ever to 200 games ... the injury was innocuous, it's just taken longer than we thought."
Fagan would be inclined to give his All-Australian midfielder another week off after watching his patched-up side dominate the Magpies.
Recruits Oscar Allen (three goals) and ruckman Sam Draper were terrific while Logan Morris (three goals) dominated the air and Ty Gallop again impressed in his unfamiliar defensive role.
Will Ashcroft (36 disposals, one goal) kicked a terrific goal and commanded the midfielder alongside Lachie Neale (29 touches).
Ashcroft had 16 touches in the final quarter against St Kilda on Saturday after Fagan had poked him to step up.
"I think he knows how good he can become .. but that last quarter last week gave him a lot of confidence," Fagan said of the 21-year-old, two-time Norm Smith Medallist.
"Hopefully he can become one of those players we look to now to lead us on the field and get us going."
Two wins in six days has got the Lions back on track but the coach, while ecstatic with Thursday's performance, remains wary.
"That's when the sledgehammer's just waiting around the corner, when you start to think that," he said.
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