The Ivorian midfielder joined the Portuguese side over the summer after falling out of the picture at Parkhead under Ange Postecoglou having made no first-team appearances since October last year.
The 24-year-old, a Neil Lennon signing who cost Celtic £2million after moving from Israeli side Bnei Yehuda in January 2020, has started four of the last five games for the Premeira Liga outfit.
However, his most recent outing, against Boavista, turned into a nightmare after Soro was given his marching orders with just 10 minutes on the clock for a late challenge that caught opponent Gaius Makouta on the ankle.
The referee deemed the challenge worthy of a straight red card and Acoura, despite scoring first, went on to lose the match 2-1.
Another Celtic loanee, striker Albian Ajeti, made his first start for Sturm Graz in a 2-0 win over Austria Klegenfurt but was replaced at half time.