"Vilanova, who is recuperating from the operation he underwent on December 20, came to the training ground and greeted the players who were working out there this morning," La Liga leaders Barca told their website on Wednesday.
The 44-year-old needed a second round of surgery following an operation to remove a tumour from his saliva glands in November 2011. Assistant coach Jordi Roura has stepped in until he is well enough to return to work.
Some of the Barca players are playing for Catalonia in a friendly against Nigeria later on Wednesday and the club said goalkeeper Victor Valdes had pulled out of the match because of a foot problem.
Carles Puyol, Gerard Pique, Martin Montoya, Jordi Alba, Xavi, Sergio Busquets, Cristian Tello, Marc Bartra and Sergi Roberto will join up with the Catalonia squad later in the day.
Vilanova was released from hospital on December 22 and began a course of chemotherapy and radiotherapy.
Club president Sandro Rosell said on Friday he should be back midway through January and would alternate work with his treatment.
Vilanova was sidelined for around three weeks in 2011 before returning to his job as assistant to Pep Guardiola and then taking over from his close friend at the end of last season.
Under his stewardship Barca have made a record-breaking unbeaten start to the league campaign and have a nine-point lead over second-placed Atletico Madrid.
Their opening match of 2013 is at home to city rivals Espanyol on Sunday.
