The pair were thrown into the action early in the second half at St Mary's Stadium and the changes had the desired effect as each player found the net in a final half hour that saw Mourinho's men score three goals to secure the points.
|10/1||Willian is 10/1 with William Hill to open the scoring against Derby|
"They were important," Mourinho said. "They gave the team another dynamic.
"They have one-on-one, they have speed, they have transition. The team loses the ball and they are very fast.
"Since they came on, we started pressing them really strong and really intense.
"The situations were arriving and finally we scored a goal that opened the door. In the first half, we had a lot of chances to score. In the second half, with Willian and Oscar, we changed things and after the goal, everything was under control.
"And the result was much more (a chance) of being two, or three, or four, rather than an equaliser from Southampton."