Ahead of Monday night’s Premier League clash at Old Trafford, Chelsea and Manchester United remain embroiled in perhaps the most contentious transfer saga of the summer. The Blues have already brought in Brazilian attacking midfielder Willian from Anzhi Makhachkala this week on a £32 million deal, but that hasn’t slowed speculation that Wayne Rooney may also be added in a move that could involve Juan Mata going to United.

Rooney has been linked to Chelsea for most of the summer, and the 27-year-old has reportedly made private statements that he expects to join the club. Chelsea manager Jose Mourinho has strongly suggested that they will make another bid for Rooney after Monday’s match in an offer that could reach as high as £40 million.

Mourinho believes Rooney will be the “final piece in the jigsaw” for the Blues, according to Sky Sports. However, United may not have time to add a prominent player to replace the one they are sending to one of their chief rivals by the Sept. 2 deadline, and have been adamant that Rooney is not for sale.

Sources from both clubs told ESPN that United formally inquired about Mata. The 25-year-old Spaniard, who has also been linked to a loan move to Atletico Madrid by the Daily Mail, would fulfill United’s desire for a big name signing this summer, but Mourinho has rubbished the rumors.

"No speculation, no speculation," said Mourinho. "He's a player we all like, he's a player we all want to keep. We want more quality in the team, we don't want less quality.

"We want to add quality to the quality we have. So Juan is not a player we want to lose.

"The point is not to sell, the point is I want a 22-player squad. So if somebody comes... Do we need to sell? No, we don't.”

Samuel Eto’o also continues to be linked to a move to Stamford Bridge and could be included with Willian on a double signing. Eto’o, 32, played for Mourinho at Inter when they won the 2010 UEFA Champions League, and Anzhi are looking to cut costs. The Telegraph reported that Mourinho does not want the striker’s possible addition to become public until after the match with United. The fee for Eto’o is believed to be at about £2 million.

Meanwhile, Liverpool are interested in bringing in winger Victor Moses on a season-long loan, according to the Daily Mail.  The 22-year-old was not part of the Chelsea squad that faced Aston Villa on Wednesday and has been left out of the squad for the Manchester United match. Chelsea are seeking a £2 million fee for the loan deal.