This was dress-down Saturday, such was the relaxed feel about it ahead of the serious business on Tuesday, and afterwards Arsène Wenger was a satisfied manager as he savoured victory while providing “a breather” for his elite.

Yet, while Arsenal’s young men of tomorrow showed there seems no end in prospect to Wenger’s harvest of young talent, one of his more experienced personnel here yesterday, Nicklas Bendtner, offered his manager a fine audition of what he could offer against Manchester United. Bendtner, who said only recently there had been times this season where he “could not put a foot right”, scored twice to bring his tally to 14 goals for the season.

Admittedly, he may have profited yesterday from David James’ 14th-minute aberration before confirming Arsenal’s victory with a penalty just before the interval, but the 21-year-old Dane demonstrated a desire not always evident in Emmanuel Adebayor at Old Trafford on Wednesday night.

The latter’s dedication to the Arsenal project has been questioned, not least because he has been linked with Barcelona and AC Milan. It should give Wenger cause for contemplation as he selects his line-up for Tuesday night. The Frenchman understandably preferred not to reveal anything, but he said of the Dane: “I always believed in him. He is developing well and showed that again today.”

Pompey, without Glen Johnson, Niko Kranjcar and Younes Kaboul, provide a rather more limited gauge of a striker’s prowess to Sir Alex Ferguson’s men. But Bendtner, leading the line with power and purpose, splendidly complemented the virtues of the 20-year-old Carlos Vela. If there was one frustration for Wenger yesterday it was that Andrey Arshavin’s exhibition here, as player and captain, showed how significant an absence the cup-tied Russian will be on Tuesday.

Otherwise this was as relaxed a preparation for Tuesday as Wenger could have planned, more so because the majority of those who will start against United were absent. None of his substitutes had started a Premier League game. But if Pompey scented blood, they were soon led up a false trail.

“There’s still work to be done,” Paul Hart had grunted after Monday night’s goalless draw at Newcastle. While Pompey are still adrift of the notional safety mark of 40 points, there will be concern. Yet, despite Arsenal’s margin of victory, there was much to please the Portsmouth manager. “If we had taken our chances, it could have been interesting,” said Hart.

James handed the initiative to the visitors by allowing Bendtner’s tame header, from Arshavin’s cross, to elude his grasp. Peter Crouch looked likely to equalise but dispatched his effort just the wrong side of a post as goalkeeper Lukasz Fabianski reduced the angle. By the break, though, Wenger’s men had confirmed victory with that Bendtner penalty after Arshavin had been felled by Sean Davis. Pompey were unhappy with referee Lee Mason’s verdict. “The players told me it was not a penalty, and I have to agree after seeing it,” said Hart.

Pompey brought on John Utaka and Kanu at the interval and were re-energised. Both had chances before, with brutal efficiency, Arsenal responded, Vela threading a sweet shot past James. When Noe Pamarot, the last defender, yanked back Arshavin and was rightly dismissed, the home faithful started vacating the stadium, the Arsenal fans scoffing: “Is there a fire drill?” It could have been worse. James later saved well from Vela. By then, the home supporters were just relieved Arsenal hadn’t sent their first team.

Star man: Nicklas Bendtner (Arsenal)

Yellow cards: Portsmouth: Kanu, Campbell, Davis. Arsenal:Arshavin

Red card: Portsmouth: Pamarot

Referee:L Mason

Attendance: 20,418

PORTSMOUTH: James 6, Pamarot 5, Campbell 6, Distin 6, Hreidarsson 5 (Kanu h-t, 6), Pennant 5 (Utaka h-t, 6), Davis 7, Hughes 6, Mullins 6, Belhadj 6, Crouch 7

ARSENAL: Fabianski 7, Sagna 7, Song 6, Djourou 7, Eboue 6, Walcott 6 (Bischoff 64min), Denilson 6, Ramsey 7, Arshavin 7, Bendtner 8 (Merida 77min), Vela 7