Celtic dropped more points in the cinch Premiership on Sunday when they were held to a 1-1 draw by Dundee United at Parkhead with centre-forward Albian Ajeti missing a glorious chance by blazing well over from three yards.

When asked about Giakoumakis, the Celtic manager said: "The scan came back actually more positive than we thought so we're hoping he'll get back into training this week, which is good news because he's missed a fair bit.

"It wasn't just the injury which we thought might be significant. We thought he might have to go back into rehab.

"But the fact the scan has come back pretty good means he can get back out training again."

Although Celtic's Europa League clash with Bayer Leverkusen will come too soon for the striker on Thursday, Postecoglou is hopeful he could feature at Aberdeen on Sunday.

"He only really missed two days of training and had a session (on Sunday)," Postecoglou added. "Hopefully he'll be back training with the group early in the week."

The former Australia head coach saw his injury issues mount further when Josip Juranovic (tight hamstring) and James McCarthy (knock) suffered first-half injuries against United.

Celtic were already missing eight players and had no experienced attacking options to come off the bench.

"We've just got to get through to the next international break," Postecoglou said.

"By then Giorgos should be available and Kyogo (Furuhashi) isn't too far away and so is Cal (Callum McGregor).

"James Forrest and Mikey Johnston will come back to help us – we're hoping post international break."