The second half got off to a sour start as Shaw had to be stretchered off after taking a knock to the head in a collision with Dani Carvajal.
Shaw was down for several minutes as he was attended to by the medical staff, during which time an oxygen mask was applied.
'Rashford was feeling something, we'll have to assess him in the morning, ' said the England manager.
Shaw tweeted after the match, thanking fans for the supportive messages he had received, and assured everyone that he is "doing fine" and "in the best hands". "I'm a fighter so I will be back soon". We'll go through some tests. It's obviously a nasty-looking fall and collision. "For certain, we won't take any chances with his health but the good news he is awake, talking and seems reasonably fine".
Playing out from the back rather than hoofing clear, England worked the ball to Kane who then found the marauding Shaw on the left and his pass was flawless for Rashford to slot past his Manchester United team mate De Gea.
Shaw had earlier set up England's opening goal with a superb through ball to clubmate Marcus Rashford.
On Shaw's overall display as he won a first global cap for 18 months, the England manager added: "It's a great contribution for the goal and it's a big thing".
Few managers are as reluctant as Mourinho to throw in young players with the big money signings the easier option for a Manager who only cares about winning today, not tomorrow.
Two minutes later Carvajal rounded Shaw and squared to Rodrigo, who cut the ball back to Saul for a first-time finish inside Jordan Pickford's near post.