The deal is well underway. Juan Mata, who hasn’t played since New Years’ Day, is on his way to Manchester United. He may be officially signed before the end of the week. The transfer will be a club-record for United, and in resolve and ammunition it will be worth double the price-tag.

It’s a dangerous game Chelsea are playing. They’re selling a world class player to a close foe, weakening themselves and strengthening that rival in the middle of a crucial season that could potentially frame English football for the next decade.

Manchester United – the Manchester United – are on the brink of an absolute disaster. Disaster is not failure to set yourself up to be slaughtered at Wembley by Manchester City.

No, it’s failure to make the Champions League that would rip to shreds the mystique of a club that is just hanging on by a thread as is. Wayne Rooney is out of contract in the summer, and if United don’t make Europe, he’s probably gone. And when top players a leaving a club, there are no top players who are coming in to replace them.

Ask Liverpool. It’s a long way back from falling out of the Champions League.

The clock is ticking. This goes well beyond Moyes. My guess is that the fallout from this season will long outlast Moyes, who you wonder if the Manchester United brass is sticking with more out of principle than real belief at the moment.

Yes, United are a mess, and United should be fearful. They’re staring a bleak abyss in the face. It’s not the financial hit that would cripple Old Trafford without European football, it’s the prestige. You just don’t know if Manchester United will have the chance to sign a player like Juan Mata starting this summer.

This January is make or break. And by inking Mata, the Red Devils just broke it open.

Players of Mata’s quality rarely move clubs in January. But with Mata not playing at Chelsea since he was hooked just after halftime in the New Year’s Day win over Southampton, and this being a World Cup year with Mata on the fringes of the Spain squad, he needed to move.

Jose Mourinho also wanted to play fair and let Mata go free. For whatever reason, Mourinho discounted Mata early in his second Chelsea tenure, but Mata’s solid attitude throughout the extremely frustrating first half of the season got him an out.

But United Chelsea and Manchester United have dominated the last decade of English football, and in that time, the two clubs haven’t done any business. The last player to go from Manchester to Southwest London was Juan Sebastian Veron in the 2003-2004 season, and he was a colossal bust with both clubs.

No matter the money, rivals don’t give players to other rivals. So this means Chelsea don’t consider Manchester United a threat, a rival, a team in their class.

It’s a statement, to be sure. Mata was Chelsea’s Player of the Year last year, and they’re handing him to the club they fought tooth and nail for the Premier League title for all but one of the last ten years. Chelsea and Mourinho are dismissing United.

That’s dangerous. I mean, this is Manchester United. With Mata in the team, they’re not looking so sorry anymore. You get Rooney and Van Persie up top, Januzaj and Mata behind them, Carrick behind them, and you have a top four team.

There is one spot open in that top four. Chelsea, Manchester City, and Arsenal will almost surely be there. But while Liverpool have big strengths, they also have big weaknesses. And Spurs and Everton are certainly solid teams, but they don’t exactly strike fear into the hearts of opponents.

United can go on a run and make the Champions League. And if they salvage this season, look out. Because as Ed Woodward gets his arms around the job of player recruitment, and this team licks their wounds after a torrid season, this club will be back. Man. United is the biggest sporting brand in the world. If they get a reprieve out of this season and escape with minimal damage, they won’t let a repeat happen.

So this is it. The club could go one way or another, and the rest of the season will determine exactly where. The club is down, but not out just yet. Chelsea could have had a huge role in stomping out United for good. Instead, they’ve tossed a lifeline into Old Trafford.

Mata was one of the best Premier League players last year, and when he gets to play this year, he should be back to that level. United were so frustrated all summer with player recruitment, and they’ve finally struck gold.

Look, I get that this makes business sense for Chelsea. They’re getting almost 40 million pounds for a player who never got on the pitch. They’re making a large profit on Mata from when they bought him from Valencia in 2011. But competitively It’s a risk. A huge risk.

Chelsea are counting Manchester United out. The Manchester United. That’s not wise.