Former Steaua Bucharest and Borussia Dortmund midfielder Marcel Raducanu believes the Ghana international is quick to anger and get himself sent off
The 58-year-old, who also represented S04's Ruhr rivals Dortmund in the 1980s, says the Ghanaian should be targeted during Wednesday's Champions League clash due to his temperament.
"Steaua's players need to attack Boateng," the 58-year-old was quoted as saying by Bild.
"The quicker he loses his head the more likely it is that he will either get sent off, or not play as well."
Meanwhile, Steaua coach Laurentiu Reghecampf says he is delighted to be facing Schalke, rather than Bundesliga giants Bayern Munich and Borussia Dortmund.
"Schalke are the only German team we wanted to play," he said.
Finally, Romanian striker Ciprian Marica, formerly of Schalke, says club captain Benedikt Howedes is a weak link in the side.
"Howedes may be the captain, but he makes far too many tactical and technical errors," the 27-year-old added.