Lionel Messi has accused Barcelona of disrespecting Luis Suarez and essentially kicking him off the team.
Suarez had wanted to stay with Barcelona this season, but he was told by Ronald Koeman he wouldn't be part of their plans.
Barcelona allowed Surarez to join Atletico Madrid on a free transfer.
"It will be strange to see you in another shirt and even stranger to play against you," Messi wrote on Instagram on Friday, a day after he bid farewell to Suarez in an event at Camp Nou.
"You deserved to depart for who you are: one of the most important players in the club's history, winning things as part of a group and individually. Not for them to kick you out as they have done. But the truth is nothing surprises me anymore."
Suarez and Arturo Vidal, two of Messi's closest friends on Barcelona, have been forced out this year.
"How hard it'll be not to share each day with you, both on and off the pitch," Messi added on Instagram.
"We're going to miss you so much. So many years, so many mates [a South American caffeine-based drink], dinners... So many things that will never be forgotten, every day together. I wish you all the best in this new challenge."