The Champions League winner joined Southampton on a permanent deal recently.
In the summer Southampton lost plenty of players, including their talented young left-back Luke Shaw. The England international left for Manchester United after an incredible season in the Premier League.
That move has been a resounding success. Bertrand has been excellent for The Saints this season and with that in mind Southampton made a move to bring him in permanently on Transfer Deadline Day.
According to Sky Sports Southampton signed him up on a four-and-a-half-year deal for a fee of £10 million.
Given his excellent form for Southampton that certainly seems like a decent deal for the player.
Bertrand of course owes much to Chelsea Football Club.
He joined up with the club in 2005 from Gillingham. He went on to have loan spells at Bournemouth, Oldham Athletic, Norwich City, Reading, Nottingham Forest and Aston Villa before Southampton made his latest loan spell permanent.
However whilst at Chelsea he did pick up two international caps, an FA Cup and of course a famous UEFA Champions League triumph.
Now, six days after leaving the club permanently, he has taken to Twitter to pay tribute to Chelsea and look forward to a future career with Southampton:
Thank you to all of the @ChelseaFC family for the past 10 years. Fans supported me from day one I thank you all and will never forget it.— Ryan Bertrand (@ryanbertrand3) February 8, 2015