The couple have a shared passion for horses, with Lisa a dressage rider

Thomas Muller spends much of his spare time at stables with his wife, Lisa

There's an old insult aimed at strikers going through lean spells in front of goal: they can't hit a barn door with a banjo.

With 21 goals in 22 games for Bayern Munich and Germany this season, there's no way anyone can say that phrase applies to Thomas Muller.

Not only that, but Muller appears to know exactly where the barn door is. Because he owns a horse. And it is called Dave. That's right, Dave.

Thomas Muller and his wife Lisa Muller, riding their horse 'Dave' at the Munich Indoors event this week

Muller applauds his wife as she competes in the show jumping tournament in Munich, Germany

Lisa is an accomplished dressage rider, and 'Dave' is described by Muller as their best horse

Muller tends to the horse (left) and gets ready to watch his wife compete in Munich

Muller and Lisa at the stables where he has the made-up job title of 'managing director of carrots'

Muller shared a picture of his wife, Lisa, riding the horse at Munich's Olympic Stadium before watching her compete at the Munich Indoors show jumping event this week. Lisa is an accomplished dressage rider and has won a German national title.

The 26-year-old World Cup winner is also a big fan of horses, spending much of his spare time with Lisa and Dave at stables near Munich.

Although Muller is himself forbidden to ride by Bayern, he has his own special job title when at the stables: 'managing director of carrots'.

MULLER'S A-NEIGH-ZING SEASON Bayern Munich Games: 18 Goals: 17 Germany Games: 4 Goals: 4 Advertisement

'I come here to watch if everything's fine,' he told CNN in an interview earlier this year. 'And for the carrots. I'm the managing director of carrots! I watch the dogs. Sometimes I help a little bit but it's her business.

'I enjoy it a lot. They make me feel comfortable, the attitude and what they look like and [the way they] live their lives. It's fun. It's easy to relax around horses.'

Lisa, 26, who can be seen in action riding Dave in the video below, admitted Muller 'knows more about horses than I know about football.'

'He's interested in horses so when we are together we talk about horses and not really about football,' she said.

Muller celebrates a goal for Bayern Munich (left) while Lisa watches her husband from the stands

Muller smashes home Bayern's fifth goal in the 5-1 thrashing of Arsenal in the Champions League last week

Muller's boots have 'Lisa 25' scripted on them in homage to his wife's name and his squad number

Muller also takes a keen interest in the breeding of horses and admits his 'dream' is for Lisa to ride a horse he has bred.

'Breeding is a little bit for fun,' he said. 'For sure I want to breed the best horse I can. But it's difficult and a bit of luck. But I try my best to optimise.'

Which leaves just one thing left to explain: why call it Dave?

The happy couple pose with a large beer and dressed in traditional Bavarian clothes at Oktoberfest

Muller (right, throwing beer on a TV presenter) is a known joker, which might explain the horse's odd name

Muller has gained a reputation as something of a joker. Off the pitch he is rarely spotted without a big grin across his face, and the video footage of him dancing at a club party is quite something.

So, perhaps in this jester's spirit, Muller named the horse in tribute to Only Fools and Horses?

After all, his compatriot and four-time Formula One world champion Sebastian Vettel has admitted he is a big fan of the classic British sitcom featuring the exploits of Del Boy and Rodney, who is called 'Dave' by a permanently confused friend, Trigger.

Again, perhaps he is a fan of the TV channel that shows repeats of other British sitcoms, Dave.

Alternatively, if Muller named the horse after one of his footballing heroes, perhaps it is in homage to David Beckham? Or Dave Beasant? Bayern team-mate David Alaba might be a more likely source of inspiration.