Gibson offered an attacking threat from midfield, while Atsu provided the cross from which Matt Upson converted past his own goalkeeper Mark Schwarzer.
"Christian, with his low balance, got in some really good positions and Darron's exceptional passing ability - both short and long - made the pitch very big and allowed the wingers to get in some one-on-one situations.
"When those two came on, we looked really at ease in terms of trying to score goals. Rom had two good opportunities and then, obviously, we scored and managed to get the equaliser.
"Overall, we wanted the three points - but I'm delighted we managed to rescue a point because Leicester are fighting for their lives and it is very, very difficult to come back from going behind that late in the game."