Barcelona are reported to be interested in signing Nottingham Forest centre-back Murillo, but they are braced for competition from Arsenal and Chelsea.
The Catalans are first in La Liga after 12 games, but they are level on points with Real Madrid, who have played a match fewer.
Hansi Flick's side are the leading scorers in the division having found the back of the net 36 times, but their return of 15 goals conceded is the joint worst in the top seven.
With the team looking defensively frail at times, there have been calls to strengthen at the back, especially as Flick's aggressive style of play has led to the club's backline being exposed.
CaughtOffside report that Forest centre-back Murillo is a genuine target, but Barca will have to convince the defender to join them over the likes of Chelsea and Arsenal.
Can Barcelona beat Arsenal, Chelsea to Murillo in the summer?
Forest are said to have placed an €80-90m (£70.3m-£79.1m) valuation on Murillo, and such a price could prove prohibitively expensive for the Catalans.
Chelsea and Arsenal have both made purchases in excess of £100m since summer 2023, whereas Barca have had to operate prudently in the market, signing the likes of Marcus Rashford on loan.
While the Spanish giants cannot compete financially with the might of the Premier League, they could benefit if Forest were to be relegated from the top flight as the Brazilian's price would almost certainly be lowered.
Murillo is just 23 and could theoretically still sign for Barca even if he was to join another English team, though the Spanish side may no longer have interest by the time he becomes available again.
Barcelona transfer targets: Who should the club sign in the summer?
If Barca are keen on saving money, then there are a number of centre-backs that could be available for free in the summer, including Liverpool's Ibrahima Konate.
The defender has struggled this season, but he was arguably the best channel defender in the Premier League in 2024-25, and perhaps his poor form this campaign is due to the uncertainty regarding his future.
Crystal Palace captain Marc Guehi is also set to be available for free, but he is certain to have numerous admirers, including Liverpool given they almost signed him in the summer of 2025.
Bayern Munich defender Dayot Upamecano has been linked to Real Madrid as his contract is set to expire at the end of 2025-26, but Barcelona would benefit from his addition if they were able to beat their fierce rivals to the Frenchman's signature.