Smalling made 0 passes to Lukaku in the Newcastle game, 3 to all attackers and 6 to the midfielders, out of 50 passes in total. He is nervous on the ball and the players are nervous when passing it to him, it's so obvious.
And yes, it's been mostly thanks to DDG, like it has been since Sir Alex retired, which is why he was voted 3 years in a row as best player at Manchester United, first time a player achieves that in the history of the club. Joint 2nd in most saves made this season in the EPL, most clean sheets, spectacular or difficult saves almost every game, consistent world-class performances and then some incredible ones as well like against Arsenal, where he made the joint most saves in the EPL in a single game since they started taking this stat in season 2003/2004. Says it all.