Barca reportedly considered a move for the former Arsenal and Real Sociedad forward in January as they sought cover for Luis Suarez.
The short-term switch failed to materialize, however, with the Spanish champions instead signing Kevin-Prince Boateng, who barely featured in his six months at the club.
Should Barca come calling again, though, Dos Santos – whose LA Galaxy side were beaten 5-3 by Vela's Los Angeles FC in the MLS Western Conference semi-final on Friday – believes Vela would have no problems slotting in alongside Lionel Messi, Antoine Griezmann and Luis Suarez.
Dos Santos, who played for Barca between 2009 and 2014 after also representing their academy and B team, told reporters: "Vela could fit in at Barcelona. He is a great player with a lot of quality; he has shown it in every team that has been.
"I hope a team like Barcelona is interested in Vela. He would do well surrounded by such excellent players."
Amid rumours the former Sweden international could return to Europe when his contract expires in December, Dos Santos said: "Zlatan is very mysterious. He has not said anything else after the game and if he stays he will help us a lot in the campaign. He is a player of excellent quality."