Definitely.
The left side - specifically the acres of space in front of the left side of our defence when we lose the ball - has been a huge factor in the run of poor results.
Norwich were the first to expose the weakness in the very first game after RND’s injury, when due to other injuries we were left fielding a left side of Osborn and Basham. Both Norwich goals came down that side.
Burnley were the next to exploit the weakness, with both goals coming down that flank - Robinson and Stevens played that day.
In the recent slip-ups, Middlesbrough’s first came from the same problem of there being a huge void in front of our left side defence, as did the first and third goals at Millwall.
Its the reason why Heckingbottom put Fleck back in - when by Fleck’s own admission he isn’t yet 100% - against Watford. It seems that we can’t trust any of our other midfielders to protect our slow (Robbo) and positionally weak (Lowe) left side.
Coulibaly did well to provide cover in that area against Spurs - albeit we weren’t quite as vulnerable in that match because Osborn played out of his skin at left-back. Coulibaly is plainly more athletic than Fleck who is struggling to get around the park, but Hecky clearly isn’t ready to trust him in crunch league games yet.
RND is arguably our best athlete - I know he doesn’t have much competition in that respect - and his continued absence from the left-side is really starting to hurt us.