Kostas Manolas said he has never heard of Malcom, while the Roma defender claimed even the Brazilian was unsure of his own name before joining Barcelona.
Manolas was in no mood to discuss Malcom after the highly rated winger snubbed Roma in favour of La Liga champions Barca at the last minute.
Malcom was set to complete a move to Roma from Bordeaux before Barca hijacked the €40 million (£36.5m/$48m) deal last week.
Now Malcom will go head-to-head with Roma when Barca take to the field at the International Champions Cup on Tuesday.
"I don't know who he is, I don't know him," Manolas told reporters in Dallas when asked about Malcom.