Declan Rice and Gabriel from Arsenal participated in training ahead of Tuesday’s Champions League quarter-final against Sporting.
Midfielder Rice, aged 27, departed from the England squad following a medical assessment during the international break in March and missed Saturday’s FA Cup quarter-final defeat to Southampton.
Meanwhile, defender Gabriel had to leave the pitch due to a knee issue sustained during the loss on the south coast.
Both players took part in first-team training at the club’s London Colney facility on Monday, just before Mikel Arteta’s team heads to Lisbon for the first leg of the match.
Belgian winger Leandro Trossard also returned to training, but Bukayo Saka was absent after leaving the England camp early.
As Premier League leaders, Arsenal are looking to bounce back from two consecutive defeats, including their FA Cup exit and a loss in the Carabao Cup final against Manchester City. The match on Tuesday is scheduled for 20:00 BST.
Arsenal is currently nine points ahead of second-placed City and is aiming for their first league title since the 2003-04 season, resuming their league campaign at home against Bournemouth on Saturday.
Manager Arteta and goalkeeper David Raya are set to address the media in Portugal later on Monday.