David Moyes Can't Let Javier Hernandez Leave Manchester United in January

It's that time of year.

The time of year when it appears that anything is possible. Any player can join any club for any fee. If Andy Carroll can move to Liverpool for £35 million after scoring 14 Premier League goals, then, in the January transfer window, anything is possible.

But for a football fan, it's best to proceed with caution. Sometimes it's nice to dream, but it's not reality until a player is standing on the pitch holding up a scarf.

Two weeks away from the January transfer window, it's possible to rationalise that Javier Hernandez might leave Manchester United next month. He's only started three times in the Premier League this season and he's got a World Cup to prepare for in the summer.

Players have left clubs for much less.

But while Hernandez might have reason to believe the grass is greener elsewhere, David Moyes has no reason to let him go.

Hernandez is an impact player, better suited to coming off the bench than starting games, and as such it is hard to keep happy.

But he still plays a vital role. If United are a goal down with 10 minutes to go, they turn to the Mexican. Only Ole Gunnar Solskjaer has scored more goals from the bench in a United shirt. His latest was the winner against Stoke in October.

Moyes inherited a squad that included Wayne Rooney, Robin van Persie and Danny Welbeck. But Hernandez does something the others can't. He's a finisher, or a "fox in the box" to use Arsene Wenger's unfortunate phrase.

He hasn't got the touch or technique of Van Persie or Rooney to hold the ball up and spread it about. But he can change a game in a second, and because of that, he's worth his weight in gold.

At the Britannia Stadium on Wednesday, he watched the first 58 minutes of United's tight Capital One Cup quarter-final from the bench. Four minutes after replacing Anderson, they were 1-0 up.

Hernandez didn't score, but his introduction had changed the way the game was played. His pace and movement panicked Stoke, and a back four that had look solid and organised for two-thirds of the game had conceded twice by the final whistle.

If Moyes was having any thoughts of letting Hernandez leave next month, then that should have put them to bed. Or perhaps a video of that winner against Stoke in October. That should do it.