Midfielders Busquets and Iniesta have been out with ankle and calf problems respectively, but trained with their team-mates on Friday.
Their availability for Saturday's home La Liga match against Athletic Bilbao is still to be determined, but head coach Luis Enrique was encouraged to have them involved in preparations.
Busquets has been missing for three games, while Iniesta has been ruled out for four consecutive matches.
Asked if they could face Athletic, Luis Enrique said: "In principle as they trained with the squad – but it is down to the doctors, the players themselves and their condition.
"But it is great news for everybody to have players returning, giving more playing resources to me."
Defender Lucas Digne (knee) was also back with the squad after missing the 2-1 Copa del Rey victory over Atletico Madrid last time out.
Barca have drawn five of their last nine games in LaLiga, leaving them four points behind leaders Real Madrid having played a game more.
But Luis Enrique still expects plenty of twists and turns in the title race.
"This is game 21," he said. "We cannot predict. There are going to be strange results.
"Top teams are going to continue to drop points – hopefully in our case less than the others – and as we run into the end of the season you can see how certain things affect teams. Then you can look at who is going to be champion, but it is difficult at the moment.
"At the moment there are still three teams – maybe more – in contention.
"This game is going to be difficult, like any other against Athletic Bilbao. Both of us as managers and teams know a lot about each other."
Barca won 1-0 at Athletic in August.