The duo had been training individually after picking up knocks but look to be back to full fitness and ready to go ahead of the return of La Liga.
The news will be a big boost to the team ahead of their trip to Son Moix. Barcelona had confirmed Messi had a minor quad injury which he seems to have shrugged off.
Meanwhile, Semedo was said to have been struggling with a bit of a knee injury and will be hoping to continue at right-back, although Sergi Roberto is also an option.
Ansu Fati is another player who has reportedly been having a few knee issues but also took part in the session as Barcelona prepare for their first game back.