Rafinha, 24, returned to action for Barcelona last week in their Copa del Rey defeat at Espanyol after recovering from a serious knee injury.
Former Brazil international Mazinho said his son wanted to play regular football in order to secure a place in Brazil's World Cup squad. The midfielder is set to undergo a medical in Italy on 22 January.
An ESPN report says Inter will have the option to sign Rafinha on a permanent basis in the summer for €35m (£31m) in the summer, with another €3m in add-ons. The Serie A club will reportedly be obligated to make the transfer permanent if they achieve Champions League qualification.
"Rafinha's objective is just to play," Mazinho was quoted as saying. "It's difficult for him to do that at Barcelona. There are a lot of good players [in his position] and it's been similar for five years now.
"He's had bad luck with injuries in these last two years and he just wants to play and feel happy doing what he likes doing at an excellent club like Inter. We hope that these three or four months will help him get back into the Brazil squad for the World Cup. He's going to take advantage of this chance in Italy."
Rafinha's agent also confirmed the Brazilian's imminent transfer to Italy, saying Inter is the only club his client wanted to join.
"Rafinha is very happy to join Inter. I can also tell you that Inter is the only option he wanted," Alex Boesch was reported as saying by Football Italia.
"The player is 100 per cent fit and has been for a month. He's in better shape than ever, so there are no doubts on his physical condition."