Guerrero bids farewell to Flamengo as Internacional move nears
Guerrero joined Flamengo from Corinthians in 2015 and was part of the team that last year won the Campeonato Carioca and reached the Copa Sudamericana final, where they lost to Independiente.
A ban for an anti-doping violation in October 2017 - which was suspended ahead of the World Cup - limited his playing time this season and he could not come to an agreement with the Rio de Janeiro club that would keep him at the Maracana.
Guerrero's 12-month suspension from FIFA was reduced to six on appeal to the Court of Arbitration for Sport (CAS), but the World Anti-Doping Agency successfully argued that was insufficient and a 14-month period of inactivity was imposed in May.
He posted on Instagram on Friday: "Today marks the end of a great period of my career. I gave every effort in the Flamengo shirt; there were more than 100 games and 43 goals to give joy to the Rubro-Negro supporters, who supported me a lot in Rio.
"I want to the thank president Eduardo Bandeira de Mello and the board for the opportunity to represent one of the greatest teams in Brazil."
A post shared by Paolo Guerrero (@guerrero9) on Aug 10, 2018 at 6:37pm PDT
Guerrero is expected to sign a three-year contract with Internacional, though the deal is reported to include a clause that will enable the club to terminate or suspend the agreement should his 14-month doping ban come into effect.
A Swiss tribunal in May imposed a stay of execution on the sanction handed down by CAS while Guerrero's appeal was considered.
Inter boss Odair Hellmann said: "He is not an Inter player yet, but he is a great player. He's an idol in his country and has great quality.
"When it's confirmed I'll be able to talk more about the subject, but my focus is and has to be on playing Fluminense on Monday. He's a great player, but he's not part of the group."