The Newcastle United player is currently on loan at Wolverhampton Wanderers, but he could have worked wonders at Leeds United.
While a permanent move failed to materialise during that transfer window, the emergency loan window allowed the Championship side to bring in the 31-year-old if they so wished.
Instead he headed to Wolverhampton Wanderers last week and wasted little time impressing during his debut against Birmingham City on Saturday, slotting in seamlessly beside Danny Batth and ensuring Wolves ended their three-match undefeated streak.
Wolves had conceded nine goals in their last three games so a clean sheet was more than welcome, with their fans quick to praise Williamson at the final whistle, and while there was no place for the experienced defender at Newcastle this season, it seems Kenny Jackett has made the move Leeds should have while they had the chance.
What Steve Evans’ side needs more than anything else is experience and Williamson has that in abundance.
He could have shored up a defence that has only managed to keep one clean sheet all season, and considering the amount of games Leeds have drawn or lost by a single goal, a player like Williamson could have made all the difference.
Hindsight is a wonderful thing in football, but there are few good options available at this time of the year and Leeds may have just seen Wolves ensure there is now one fewer.