Arsenal sale of Gabriel signals future is here for club's young defenders

Arsenal have finally managed to sell an outfield player this summer, with Gabriel Paulista heading back to Spain to join Valencia in a deal completed on Friday.

He isn't the defender most expected to be first out the Emirates door this transfer window -- Mathieu Debuchy and Carl Jenkinson have been looking for new homes, and Calum Chambers had been more widely tipped as the centre-back to be sacrificed in manager Arsene Wenger's squad trimming.

Gabriel's exit makes short-term sense, however, as he was staring at another season as a backup even if Wenger does stick with a back-three formation. In a longer-term sense, it must also be seen as a vote of confidence from Wenger in Chambers, 22, and fellow young Englishman Rob Holding, 21.

If Chambers does stay at Arsenal (which now looks likely), he and Holding still represent the future rather than the present at Arsenal. Wenger has Laurent Koscielny and Shkodran Mustafi as the bedrock of Arsenal's defence, and the experience of Per Mertesacker or Nacho Monreal could give either the nod ahead of the two young Englishmen in the starting lineup. Newcomer Sead Kolasinac can also be deployed in a back-three if needed.

But we already know this is Mertesacker's final season as a player, while Koscielny and Monreal are both 31 and entering the twilight of their careers. That means there will soon be big holes to fill in Arsenal's back line, and keeping Gabriel could have ensured a fairly smooth transition.

The Brazilian was inconsistent, to say the least, in his two and a half years at the club, and his hotheadedness got him into trouble at times -- whether it was getting baited by Diego Costa or lunging recklessly into wild challenges. But Gabriel seemed to fit well into Wenger's new back-three system, and his performance against Manchester City in the FA Cup semifinal was arguably the best of his Arsenal career. It seemed to showcase a new level of maturity for Gabriel, who at 26 is entering the prime age for a centre-back. It's quite likely that Valencia are getting a better player for £10 million than the one Arsenal paid £12 million for in January 2015.

Chambers, meanwhile, is still more of a promising talent than a finished article. While he started ahead of Holding for England's under-21s this summer, Chambers seems to be behind his international teammate in Wenger's pecking order. Holding was excellent toward the end of last season but has looked a bit shakier in the first games of this campaign -- the Community Shield win over Chelsea and the 4-3 victory over Leicester in the Premier League. He made several passing mistakes in both.

Wenger has never been shy about putting his trust in youth, though, and it seems he's ready to do so again. Since Holding joined from Bolton last summer, many Arsenal fans have been dreaming of an all-English central defence partnership between him and Chambers in coming years.

They certainly seem to get on well off the pitch: Holding revealed on the latest Arsenal Weekly podcast that they're even living together at the moment, as Danny Welbeck is still renting Chambers' house since his loan spell at Middlesbrough.

The sale of Gabriel seems to indicate that Wenger is still hoping they will eventually combine just as well on the pitch.

Unless, of course, it was only meant to raise funds for a late bid for Virgil van Dijk.