Wayne Rooney has been left in no doubt regarding his position at Manchester United with David Moyes, the manager, issuing a stark message that the striker is considered vital only if "we had an injury to Robin van Persie". Ed Woodward, United's executive vice-chairman, also underlined the hardline stance towards Rooney, claiming the club have no fear of a player's deal running down.

With Rooney not for sale and Woodward insisting there are no plans to open contract talks despite the England international entering the last two years of a deal that pays £250,000 a week, Moyes urged Rooney to prove his worth. "Wayne can play up on his own, he can play dropped in. Overall my thought on Wayne is, if for any reason we had an injury to Robin van Persie, we'll need him," said Moyes, speaking in Bangkok before United flew to Sydney for the next leg of their tour.

"I want to be able to play the two of them, I want to use Danny Welbeck and Javier Hernández as well. I want to give myself as many options as possible."

As reported in the Observer last week, United are relaxed about Rooney not signing a new deal. Woodward said: "There are no contract renewals that are being discussed. I am not sitting down with any player on an extension and there is no trigger date in the diary. Would we be afraid to run a contract down? Of course not."

Moyes stated that the club may reassess their position on Rooney in 12 months' time, effectively informing him he is on trial. But Moyes is intent on bringing out the best in Rooney, for club and country. "If I can give him [England's manager, Roy Hodgson] a really good Wayne Rooney, a confident Wayne Rooney, then that will benefit everybody," Moyes said.

"It's going to be a time to see how I work with Wayne. Maybe in a year's time we might have to look at something else. The first year, I have to get a chance to see the players and how best to use them. I've got to ensure it's not just him and we don't concentrate on him. Manchester United isn't about Wayne; Manchester United is about the team, the club."

Chris Smalling has undergone a second operation on the foot injury that has kept him out of United's pre-season tour, with the defender a doubt for the start of Moyes's first campaign as United manager. Ashley Young's ankle problem is also placing his availability in the balance and, with injuries to other players, including Rooney, Moyes is facing a potential crisis as he aims to hit the ground running. There was brighter news for United as Van Persie joined up with the squad in Sydney, along with the goalkeeper David de Gea.

Smalling had a first operation in May that left him on crutches, though it is thought the second surgery was relatively minor, with Moyes stating that the 23-year-old is back in light training. "You're always likely to pick up one or two knocks and niggles," he said, speaking at Sydney's Museum of Contemporary Art. "But we've got players who are starting some training back home in the UK. Ashley Young's started some training, Chris Smalling has started some light training and Nemanja Vidic [who has sciatica] has started. So we do know that if we do need them we can probably call on them.

"My preference was to come with a smaller squad because I wanted to make sure I got as many players playing minutes as possible. I didn't want to bring players who would travel halfway around the world for three weeks and end up not playing enough games."

Regarding Van Persie, Moyes said: "Fortunately, Robin will join us here in Sydney, which will help us a lot. It's a big part of our preparations, coming here. We're looking forward to a good week's training."

After Saturday evening's shock 1-0 defeat by Singha All Stars in Bangkok in Moyes's first game as manager, United will hope to defeat the A-League All Stars on Saturday in Sydney.