For a few years in Barça's Ciutat Esportiva the training sessions are held behind closed doors or opened to the media during the first 15 minutes, during which players usually do a "round" before to start warming up for the session. The first team's intimacy is guaranted through measures like these, avoiding that cameras record the drills (of which some are tactical) that could be harmful for the club in case they were published, revealing tactical details to the opponents. With the season over though, Barça's official website published a video in which we can see the first team divided in three teams on a smaller pitch doing a competition.
A drill in which we can see the players' skills in a game simulation, with a lot of rhythm and the goal as main objective. Goals from Messi, Neymar, Iniesta, Rafinha and most importantly Mascherano, combined with great saves like Ter Stegen's after a header from Messi. In addition, a more vertical style of play (due to the short ditance with the goal), like it is shown in that video.