The Toffees have made six signings during the course of the summer transfer window, having recruited Jake O'Brien, Iliman Ndiaye, Jack Harrison, Jesper Lindstrom, Tim Iroegbunam and Asmir Begovic.
Everton are still keen to make further additions after experiencing a difficult start to the Premier League season, losing 3-0 to Brighton & Hove Albion before falling to a 4-0 defeat against Tottenham Hotspur.
According to The Athletic, Everton are currently in negotiations with Lyon over a season-long loan deal for Mangala.
The Belgium international could return to England just eight months after joining Lyon from Nottingham Forest for £30m in January.
Mangala started Lyon's Ligue 1 opener against Rennes, but he was an unused substitute in Saturday's home clash with Monaco.
Leicester set to sign El Khannouss
Meanwhile, Leicester City are reportedly on the verge of signing Bilal El Khannouss from Belgian side Club Brugge.
After recently signing Oliver Skipp and Jordan Ayew, Leicester are set to continue their transfer business by adding El Khannouss to their squad.
According to the Daily Mail, Leicester are set to sign El Khannouss for around £20m after the Moroccan opted to turn down interest from Champions League clubs.
There is a belief that El Khannouss could be unveiled in the next 24 hours which would make him available for Saturday's Premier League home game against Aston Villa.
The 20-year-old has spent his entire senior career with Genk and is set to leave the club after making 94 competitive appearances in all competitions.
He was also part of the Morocco side that won a bronze medal at the 2024 Olympics, where he contributed one goal and two assists.
Leeds in talks over Tanaka move
In the Championship, Leeds United have reportedly opened talks with Fortuna Dusseldorf over a move for midfielder Ao Tanaka.
Leeds are looking to strengthen their midfield options after selling Glen Kamara to Rennes earlier in the summer transfer window.
They have seemingly identified Tanaka as a potential target, with the Daily Mail reporting that Leeds are in negotiations with Dusseldorf to sign the Japan international.
The report claims that the 25-year-old has a £2.65m release clause in his contract and could travel to England this evening if Leeds can quickly agree terms over a move.
Tanaka has made 95 competitive appearances since joining Dusseldorf in the summer of 2021, contributing 10 goals and eight assists.
The midfielder has played every minute of Dusseldorf's first four competitive matches of the new campaign, but there is a possibility that he made his final appearance for the club in Sunday's 2.Bundesliga win over SSV Ulm 1846.