The 18-year-old midfielder started the Championship game for Leeds at Elland Road on Saturday afternoon and played for 85 minutes.
Cook took two shots, had a pass accuracy of 79%, attempted one dribble, and made one interception and two blocks.
The performance of the teenager was far from impressive, but former Leeds coach Abbott understands why he struggled against the Millers.
“We are criticising Lewis Cook, but the way that Leeds set out to play that game, they are missing midfield out a lot,” the 51-year-old told TV Yorkshire.
“He needs to get on the ball if he is going to make an impact, he needs the ball, he needs to play through him at times.”
Leeds failed to make it three wins in a row in the Championship, as they suffered a 1-0 defeat to Rotherham.
Joe Newell’s headed goal in the 54th minute proved to be the difference between the two teams.
Over the course of the 90 minutes at Elland Road, the Whites had 60% of the possession, took 14 shots of which just three were on target, and earned nine corners.
Visitors Rotherham had 40% of the possession, took nine shots of which three were on target, and earned four corners.
Leeds are 16th in the Championship table at the moment with 19 points from 17 matches, just four points above the relegation zone.
The Whites will take on Queens Park Rangers away from home at Loftus Road in the Championship next weekend.