Arsène Wenger has warned Danny Welbeck that he may have to move to the flank if he wants to remain an Arsenal starter. The manager has Olivier Giroud available again for Saturday’s visit of Manchester United and although the France international will be a substitute at best, the competition for the lead striker’s role at the club is set to intensify.

Welbeck has said on numerous occasions since his transfer deadline day move from United to Arsenal that he wants to embrace the opportunity to play in his preferred position through the middle. He will remain as the centre-forward in the late kick-off against his boyhood club, provided that, as expected, he overcomes the effects of the hamstring injury he picked up on England duty against Scotland on Tuesday night.

But Giroud’s return, weeks ahead of schedule, from the fractured tibia that he sustained at Everton on 23 August, promises to change the dynamic. Giroud, who lacks mobility, can only play as a No.9 whereas Welbeck, whether he likes it or not, has the pace and application to work in wide areas.

Welbeck has had the best part of three months to stake his claim up front and he has scored five times in 12 starts for the club, three of them coming in the Champions League home win over Galatasaray. His performances have been energetic and his star has been enhanced by his form for England, for whom he has five goals in six appearances. He has generally played in a central role for the national team.

The 23-year-old felt that his natural instincts were curtailed at United, where he was regularly played out wide – in addition to being in and out of the line-up. “People can say I’ve not scored enough goals but you see the best strikers on the wing in a four-man midfield and see if they score goals,” Welbeck said, after his electric performance against Galatasaray. His versatility, though, could remain his curse.

“One of the main reasons [for Welbeck signing] was that he wanted to play,” Wenger said. “It was not a condition [to play as a central striker], it was just that he plays. You can have outstanding goalscoring records from players who play wide or central – that is not the problem. When you are a player, you want to play.

“I don’t think playing on the flanks will stop him from scoring. He had chances the other night [in the Scotland game] when he played on the left. With his pace, [Cristiano] Ronaldo played all his life on the flanks and scored more goals than games he played. I don’t think that will stop Welbeck. What is a problem for him is to play.”

Wenger made the point that he has played something that resembles a 4-4-2 formation of late, with Alexis Sánchez pushed up towards Welbeck, which might raise the prospect of Welbeck working alongside Giroud. At present, though, it is difficult to see Wenger moving the in-form Sánchez from his advanced central role while the manager has plenty of other options in wide areas.

“In some games you adapt,” Wenger said. “The modern player is adaptable. Sánchez can play wide left and wide right as well as through the middle. Welbeck as well. It is so important on the flanks to have pace and work rate. Sometimes in games, you have to put them there because they can absorb the quantity and quality of the work.”

Wenger described Welbeck as being “comfortable” on the left. “He played there at a young age and when you play football, you get habits in the position you play,” Wenger said. “You feel at home a little bit. He looks comfortable there because he knows what to do. It is linked sometimes with your preferential vision as well. We all have preferential vision and sometimes players see better on their right and sometimes players see better on their left. So when you have better right vision and you play on the left, you see the whole pitch.”

Louis van Gaal, who took over as the United manager in the summer, said in September that he sold Welbeck because the player was below the standards required at Old Trafford. The script surely calls for Welbeck to score against van Gaal’s team.

“You take every challenge in a positive way and that’s what Danny did,” Wenger said, when Van Gaal’s assessment of Welbeck was put to him. “You have to understand that Van Gaal had not had Welbeck under his command for a long time and it’s always very difficult to know the players well when you see them for three or four weeks. Wayne Rooney and Robin van Persie have an exceptional goalscoring record – Welbeck had two quality players in front of him. What he needed was a chance.”