Bertrand is more at home playing on the left and appears to be a ready-made replacement for Luke Shaw, who moved to Manchester United earlier this summer.
Young Matt Targett has impressed in place of Shaw in pre-season, but Bertrand adds some much-needed depth to a rapidly depleting Saints squad.
With no rumours linking Southampton to signing anyone, let alone Bertrand, this is welcome news in a week that has seen club stalwart Morgan Schneiderlin publicly voice his anger at not being allowed to leave for Tottenham Hotspur.
Also, the signing, albeit merely a loan signing, keeps in line with the Hampshire side's ethos of recruiting young, English talent. This is a move in the right direction.
It's also encouraging that Koeman's reputation has helped Bertrand make his decision to join Saints. Speaking to the Southampton website, Bertrand said:
"For me personally, this is another chance to play and a chance to join a fantastic club that's moving in the right direction.
"With the set-up the club's got, the manager it has coming in and the ethos it has, I thought this was a perfect match.
"The manager's name speaks for itself, so to play under somebody like that will be good for me. His ethos and the way he plays matches my game."
Here's hoping Koeman's name can help draw some more young European talent to the south coast.