Scott McDonald is considering cutting short his vacation

Celtic striker Scott McDonald is considering cutting short his summer vacation to ensure it hits the ground running next season.

Australia has signed a new five-year contract with the Clydesdale Bank Premier League champions back yesterday after a three-week spell on the other side of the globe to play in his country's World Cup.

And it May demonstrate its commitment to the Parkhead club by foregoing an additional break given to players involved in international duty.

McDonald, who has scored 31 goals for Celtic following his £ 700000 move from Motherwell last summer, said: "To return to the field after three weeks, I am chewing a new piece, but I need a little rest.

"I've just finished with international obligation, so I'll get a couple of weeks and refresh the mind and body and return as hungry as ever.

"I think everyone is back on July 4, but everyone who has been international law is authorized a further pause.

"I'm weighing it at the moment and see what I feel after the next two weeks and see how I feel refreshed.

"If I feel good enough, I'll be back the same time as everyone, because I do not really miss anything.

"I know I've done the same thing everyone. That is what is best for me and best for me is to return in early pre-season.

"I think if you have a very good pre-season, it could make the difference for the rest of the season."

McDonald presented in two World Cup against Iraq after helping his club Rangers pip the SPL title.

"It was a hell of a busy schedule, but it is finished now," about 24 years.

"I like to play for my country, but it was the longest season of my career.

"I played 50-odd games and it was a very large number on the body. It's just right now for a couple of weeks off.

"You can no longer strong week, week by reading. I learned a lot during the season.

"There have been times when I felt tired in training, but there are ways to ensure that never happens again."

McDonald is the only man to sign on Celtic so far this summer, while the Rangers are expected to complete the purchase of their third attacker in a week with Kyle Lafferty following Kenny Miller and Andrius Velicka.

Celtic had made an offer for Lafferty, but McDonald is unfazed by the reinforcements coming to Ibrox.

"I'm not really concerned with what happens on the other side of the road," he said.

"They are all very good players, two of them are proven in the SPL, Kenny and Velicka, so they are underway to improve Rangers team.

"But we are quite convinced the team that we have here at the moment is quite good and we hope to do if four (titles) in a row."