That wasn't the end of the list, of course, with skipper John Terry, Andre Schurrle and the enigmatic Fernando Torres also being included in the Chelsea players' selfie.
And spirits seemed high within the squad ahead of their Premier League opener, despite Jose Mourinho still needing to make key selection issues - namely who should start in goal for his side.
Earlier, Luis had tweeted a picture of himself with Azpilicueta, Cech and Fabregas during cold-water training.
The Brazilian completed a £15.8 million move to Stamford Bridge from Atletico Madrid this summer, with Fabregas also joining the Blues from Barcelona for a fee believed to be around £27m.
It looks as though the Blues' new-look squad are bonding well, although tensions may be higher tomorrow, when Mourinho has said he will announce his no.1, along with other key positions.
Courtois and Cech are fighting it out to be named Chelsea's primary shot stopper, with there being strong suggestions that the goalkeeper who doesn't get the nod will leave the club before the transfer deadline passes.
Chelsea travel to Turf Moor for their Premier League opener against Burnley on Monday night, where the west London side will no doubt look to get their season off to a strong start.
Mourinho's men finished third in the league last season and also reached the Champions League semi-finals but ultimately ended the campaign trophyless.