Ba finished the 2011-12 campaign as the club’s top league scorer with 16 goals including another hat-trick against Stoke City.
He has continued his free-scoring ways this season, bagging 13 league goals to lie joint second in the overall chart behind Manchester United’s Robin van Persie (16).
Chelsea are desperate for backup in attack for Spanish international Fernando Torres who is the London team’s most-used outfield player this season.
Options up front have been limited following the exits of Didier Drogba and Salomon Kalou in the close season and the decision to allow Romelu Lukaku to join Premier League rivals West Bromwich Albion on loan.
England forward Daniel Sturridge has joined Liverpool following an injury-interrupted season with the Stamford Bridge club.
Chelsea can go back up to third in the league if they win at home to neighbours Queens Park Rangers later on Wednesday.