Mata's fate has been nothing but contentious since Jose Mourinho replaced the Spaniard in midfield with Brazilian international Oscar. Much cogitation has been given to Mata's future; links with Paris Saint-German, Atletico Madrid and Inter Milan have all been posed, but Manchester United seem the first to make an official inquiry.
If United's first offer is £35 million, it would stand to reason they value the Spanish attacking midfielder for at least £40 million. As such, Chelsea would be wise to reject the first offer and make Manchester up the ante.
From David Moyes’ perspective, the transfer would signify a changing of the guard. Mata doesn't fit in United's current system. His preferred position is behind the striker in the "number 10" position—where Wayne Rooney prefers to play as a secondary striker.
Playing Mata on the wing would be a waste of both his talent and the transfer fee; so if the deal gets done, it would seem either one or two of Rooney, Danny Welbeck, Javier Hernandez or Robin van Persie will be on their way out come the summer.
The Scottish manager's preferred play style with Everton was the 4-2-3-1, though at United he's been forced by both the squad’s profile and injuries to play variations of the 4-4-2. Mata has proven to be an expert fit in the 4-2-3-1 formation—scoring 11 and assisting on 17 goals in the CAM role last Premier League campaign.
During his brief reign at Stamford Bridge, Andre Villas-Boas acquired the Spaniard from Valencia for a reported £23.5 million in 2011. Voted the two-time Chelsea Player of the Year, playing under four different managers and having won an FA Cup, the Europa League and the Champions League, Mata's time in west London has been a relative success.
Chelsea would certainly prefer a foreign contender to see United's wager and try to outbid them—thus avoiding the sale of Mata to an English side.
If that doesn't happen, and United are the only suitor, the solace for Chelsea supporters would be in the mammoth fee. If Manchester is forced to pay upwards of £40 million for Mata, the would-be sour taste of selling a fan favourite might sweeten a bit.
Chelsea owner Roman Abramovich is being forced to curb his spending habit due to UEFA Financial Fair Play rules; a record incoming sum, netting at least £11 million in profit, would give the Blues' ledger a real boost.
The transfer’s easier to swallow considering the Red Devils are currently seventh in the Premier League table; and civil diplomatic relations this month may set the table for Mourinho's dream striker Wayne Rooney to be attainable come the summer.
If it weren't for the domestic implications and silverware rivalry between the clubs over the past decade, the deal would have been done already. The “book” on these things states you should never sell to your rivals, but if a rival's willing to pay an amount greater than the GDP of 10 U.S. states—you've certainly got to think about it.
To answer the title question: "Juan Mata to Manchester United: Smart or Not Smart?"
When a player's rotting on the bench, waiting for the preferred option to either get hurt or tired—it seems too good an opportunity to pass on £35-40 million.
Final verdict: Smart.