Manchester United are continuing to work on a deal for Patrick Dorgu before the transfer deadline, sources have told ESPN.

Lecce have already knocked back an offer of 20 million ($20.9m) plus 5m in add-ons for the 20-year-old Denmark international.

Sources have told ESPN that talks between the two clubs are ongoing and that there is growing confidence an overall package of close to 40m can be agreed.

Ruben Amorim is keen to add a left wing-back to his squad in January. United, according to sources, have also explored the possibility of triggering their 18m buy-back option to re-sign Álvaro Fernández from Benfica.

The former Old Trafford academy graduate, who has impressed in Portugal, is considered a fallback option if a deal for Dorgu cannot be agreed. Should either Dorgu or Fernández arrive, United will listen to loan offers from Tyrell Malacia.

There's hope that Luke Shaw is close to a comeback from injury and a temporary move until the end of the season would allow Malacia to play regularly. The Dutchman has made seven appearances this season after spending more than a year sidelined with a knee injury.

Sources have also told ESPN that United will listen to loan offers for Casemiro before Monday's deadline. The Brazil international has started just one of the last 11 games and has been an unused substitute in the last six matches.

His last appearance was in the 2-0 defeat to Newcastle on Dec. 30. Roma have expressed interest in signing the 32-year-old until the end of the season.

Sources have told ESPN that United are willing to pay a portion of Casemiro's wages -- more than 300k-a-week -- to make the move happen.