He had undoubtedly lost trust in his stroke, however, the putting with the eyes closed drill has helped him regain confidence in his stroke and it might become 'permanent'.
Sergio claims that he has been doing it on and off for years; even during his Masters win in 2017.
During the Sanderson Farms Championship, it is the first time I have noticed him doing it with his lag and short putts.
Does he actually do it all the time? Will he keep doing it?
Have you ever tried it as a drill? Would you dare/Have you dared try it in competition?