Chelsea have named Celtic's Matt O'Riley as a candidate to replace Conor Gallagher should the Englishman have his departure from Stamford Bridge sealed, according to reports.
Gallagher continues to be pursued by Athletico Madrid after the Spanish side agreed a £34.1m deal with the Blues, but the player is yet to sign-off on making the move as he weighs up his playing future.
The 24-year-old has already rejected a two-plus-one-year extension from the Blues who now view him as a squad player under new head coach Enzo Maresca and informed him that he will not be part of the first-team dressing room when he returns from holiday.
Gallagher is a popular figure amongst Chelsea's dressing room and captained the club in several matches last season under former boss Mauricio Pochettino, but is now being advised he is not part of their long-term plans.
Recruitment efforts searching for a new midfielder to succeed Gallagher are now ongoing at Stamford Bridge and O'Riley is amongst the names under consideration, as reported by Sky Sports.
O'Riley previously scored against Chelsea in Celtic's 4-1 pre-season friendly win over in the United States
The 23-year-old recently scored against Chelsea in the Scottish side's 4-1 pre-season victory and admiration from him has only continued to grow amongst Maresca's coaching team and transfer negotiators.
O'Reilly is attracting interest from other Premier League suitors in the form of Southampton where manager Russell Martin previously worked with the Denmark international at MK Dons.
Reigning Europa Conference League champions, Atalanta, have already had bids rejected by Celtic for the midfielder who scored 19 goals across 49 appearances in Scotland last season.
However, any move for O'Riley is likely to hinge on the departure of Gallagher who can either accept Chelsea's latest proposal, join another club or see out the remainder of his existing contract.
Gallagher's current contract a Stamford Bridge is set to expire at the end of the coming campaign and a number of clubs have shown an interest in signing the 24-year-old this summer.
The midfielder rejected the deal, and once again turned down the same terms last week after Diego Simeone's side had a bid accepted.