Alan Hutton believes Leeds United are in danger of being relegated from the Premier League this season, if they do not improve their defence.
The Whites are currently 12th in the top-flight table in their first campaign back in the division in 16 years.
Marcelo Bielsa's style of football at Elland Road has received many plaudits, but has also faced its fair share of criticism due to Leeds' defensive vulnerabilities.
The Yorkshire-based club have conceded 33 goals in their opening 17 Premier League games - which is the second-highest in the division, behind fellow newly-promoted side West Bromwich Albion (39).
With the January transfer window now open, Bielsa has been linked with bringing in numerous new players including Adama Traore from Wolves and Reading's 18-year-old star Micheal Olise.
However, former Aston Villa and Scotland defender Hutton has called on Leeds to focus on improving their defence, rather than their attack.
Speaking to Football Insider, he said: "I’d be more worried about my backline than these forward-thinking players.
"We know what Adama Traore can bring you – he’s pacy, he’s intelligent he’s a willing runner. The same goes for Michael Olise.
"You’re always mindful of burnout. I know they train very hard, they play at 100 miles per hour. You will need reinforcements.
"But for me, it’s the backline. I looked at it the other day and Ayling was playing a centre-half and he’s a right-back. Alioski, who’s a winger, was playing at left-back. Dallas playing as a midfielder. I’d be more worried about that.
"They’re conceding a lot of goals, a lot of goals from corner kicks. I would want to shore up the defence first because you can play the best football and you can attack, attack, attack, but if you’re conceding that many goals you’ll end up going down. That’s the way the Premier League is."
Leeds are currently without central defensive trio Liam Cooper, Robin Koch and Diego Llorente due to injuries.
Luke Ayling and Pascal Struijk - who usually play as a full-back and holding midfielder, respectively - have moved into the centre of defence to help Bielsa's side.
The Whites were beaten for the first time in two games at the weekend, as Tottenham Hotspur struck three past Illan Meslier without reply.
Now, Bielsa and his squad will be preparing for an FA Cup third-round tie against League Two club Crawley Town this weekend.