Many players like Del Potro who is a shy and nice guy in personal life, Nadal is also often liked, with Djokovic there are more mixed feelings among players. Besides, in Fed's personal case, it has been talked a lot about how their story started, the DC 2006 and the accusations of Djokovic faking against Wawrinka ...
Del Potro has always been very nice when talking about Roger, Roger felt bad for him after his loss in the French open semi in 2009, I can witness that I saw Fed's interview on court just after the match and he looked very genuinely moved by the big young boy's tears.
Then there was Del Po's injury and Del Po said that Fed send him a lot of messages and asked his infos, he was surprised about that and appreciated it.
For the anecdote last week a journalist asked Del Po if Swiss guys had called him in the street or just lfet him quiet in the street like the "good Swiss" they are, and Del Po answered : only one called me, it was Roger in his car while I was crossing a bridge