Interviewed in Dallas before the pre-season friendly match against Champions League conquerors Roma, the Brazilian spoke of his sibling's quality.
SPORT report the current Barcelona number 12 as commenting: "I would like to see him again at Barça, because I think he fits perfectly in this team,"
The Italian-born Spanish international has appeared 31 times for his adopted nation, and may seek a transfer home. His game time in Germany has become a lot more fragmented due to James Rodriguez's loan deal and Corentin Tolisso's meteoric rise.
Sons of 1994 Brazilian World Cup winner Mazinho, the pair will both be looking for considerably more first team action than has been the case in the last few campaigns.
More self-effacing with his own future, Rafinha spent last season on loan at Internazionale. Enjoying a fruitful spell in Italy, he helped I Nerazzuri qualify for the Champions League in a final day showdown win away to Lazio.
With an option to buy at €35m, rumours of a return to Serie A are doing the rounds. Rafinha is focused on Barcelona however, but does admit he needs to play more often or think about his career path.
"Right now I'm away from all this. My head is only in the pre-season games. What I want is to be physically well and leave this issue in the hands of my representative," he said.
"It is clear that anyone wants to play in the place where he has more minutes, either here or outside , in another team that is not the Barca."
Whether Rafinha and Thiago are to team up in Catalonia for next season's La Liga or not, there's definitely mileage left before the each window shuts across the continent.
If it's to be Inter, Bayern or Barça, it would take some rather large transfer fees to either reunite, or completely break up these brothers.