Wenger loses again as Song follows Van Persie out the revolving door

After departure of their Dutch talisman, Arsenal now sell midfield mainstay to Barcelona for £15m

Arsenal accepted the loss of as second regular first-team player last night when agreeing a £15million fee with Barcelona for Alex Song, who will have a medical in Spain today. Two days after selling Robin van Persie to Manchester United for £24m, Arsène Wenger agreed it was "frustrating" to lose another senior player, who played 46 games in all competitions last season.

Arsenal may yet bring in a replacement – Real Madrid's Nuri Sahin remains a target – but Wenger insists they are well stocked in midfield. "We have plenty of players at the moment," he wrote in the match programme before yesterday's disappointing goalless draw at home to Sunderland, from which Song was left out. "We have nine or ten and if Alex goes we will still have somebody else in the defensive area."

Mikel Arteta and Alou Diaby, who is back from injury, played there yesterday, with Aaron Ramsey coming on later. After spending £40m on three new players in Lukas Podolski, Olivier Giroud and Santi Cazorla, Wenger has balanced the books by adding Song's fee to Van Persie's.

Meanwhile, Manchester City hope to sign the Roma midfielder Daniele de Rossi in defence of their Premier League title, although the Italian club say they must increase their offer to nearer €30million (£23.5m). Reports from Italy say City bid €25million for the man, who scored for Italy in their midweek defeat by England.

City's manager Roberto Mancini, having signed only Jack Rodwell from Everton and said that Manchester United are even firmer favourites after securing Robin van Persie from Arsenal, wants two more players in the remaining fortnight before the summer transfer window closes.

Mancini has made defending the Premier League title his club's priority, ahead of the Champions' League, and wants to avoid the sort of unexpected away defeats that almost cost them last season.

City begin their League programme against newly promoted Southampton today at the Etihad, where they were impregnable last season. The manager did not complain about losing at Arsenal and Chelsea but was upset by the other three away defeats. "There are some moments when maybe you can't win because the other team play better but you can't lose a game like Everton, Swansea, Sunderland where you didn't deserve to lose," he said.

United will assess Van Persie's fitness today before deciding whether he starts at Everton tomorrow.