In the world of tennis, Andy Murray remains one of the sport's most famous and well respected superstars.

A skilled player and a popular champion, Murray is one of those guys who, for years, you just couldn't see slowing down.

However, this year has been a rather dismal one for the Brit, as he has been plagued by a troublesome hip injury - forcing him to miss much of the season. 

His fitness problems first became a serious issue in the spring after sustaining an elbow injury in March which then affected his performances at the Monte-Carlo Masters in April. Murray's struggles continued in the Barcelona and Madrid Opens, as well as the Internazionali BNL d'Italia in Rome. 

These days, Murray is dealing with a lingering hip injury, which has forced him to back out of competing in professional tournaments for the remainder of the year.

However, he finally made his 'competitive' comeback on Friday by featuring in an exhibition set at the Mubadala World Championships, replacing for Novak Djokovic, who pulled out at the last minute.

It wasn't the best return, however, as Murray lost against Roberto Bautista Agut 6-2, but was happy to be back in action and admitted he needs to keep improving his level of fitness after playing his first competitive set in nearly six months.

“When you haven't competed for a while, it takes time to get up to that pace,” Murray said, as per The Express.

“I started to feel a bit better towards the end but I’ll need to keep improving, for sure.

“It was nice. I was planning on stopping here for a couple of days on the way over to Australia to get some practice in with the guys here.

“It was unfortunate that Novak was unable to play so I agreed to play a set. I was very lucky to be able to come out here and play in front of everyone.

“It was good fun. I’ve missed it.”

Murray has now flown out to Australia and is expected to play the Brisbane International, which gets underway on Sunday before the Australian Open starts on January 15.