The principality based side lost 3-1 to Valencia in the first leg of their qualifying tie for the groups, with the home leg coming up next week. This puts a question mark over the future of the Portugal international, who is thought to want to play in the competition.
The 28-year-old joined the club in 2013, and has since seen big-name players such as James Rodriguez and Radamel Falcao leave either temporarily or permanently as the spending has been cut. However, he has stuck with them, and last season managed four goals and six assists in 37 Ligue 1 appearances.
The midfielder also helped the team to get to the quarter-finals of the Champions League, beating the Gunners along the way. Having seen his talent up close, Arsene Wenger may now want to bring him to the Emirates Stadium to bolster his team in the middle of the park.