Now an experienced defender at the age of 31, London-born Bertrand, most recently of Southampton, will add a vast amount of know-how to Leicester’s ranks, following his move to King Power Stadium.
The 5ft 10ins left-back made his first steps in the game at Gillingham, joining the Essex-based club’s academy at the age of nine, until Chelsea snapped him up seven years later.
Upon earning his first professional contract in 2006, Bertrand enjoyed a series of nine loan spells at seven different clubs, starting with two stints at AFC Bournemouth, followed by time with Oldham Athletic.
It was during back-to-back loans with Norwich City where the young full-back really started to make an impression, however, playing a total of 60 games for the Canaries between 2008 and 2009 – only at Southampton has Bertrand made more appearances across his career.
His first senior goal would then come during a season long-loan at Championship side Reading, against Derby County in March 2010, while the earlier part of the campaign saw Bertrand managed by Brendan Rodgers for a brief spell.
The 2010/11 season proved to be a significant one for the Chelsea defender. Starting out at Nottingham Forest, in the second tier once more, the East Midlands club secured a sixth-place finish and consequently a play-off berth.
Bertrand, however, was recalled by his parent club in January after 19 league appearances for Forest and made his Chelsea debut as a 21-year-old on 11 April, 2011, in a Premier League clash with Birmingham City. Coming off the bench to replace England’s first choice left-back Ashley Cole, Bertrand claimed an assist as the Blues triumphed 3-1.
His first start for the club would have to wait until the following season. Carlo Ancelotti departed, replaced by André Villas Boas, and after Bertrand had signed a new four-year contract that summer, he made his full debut in a League Cup tie with Fulham at Stamford Bridge.
He would feature three times in the competition, as well as playing seven Premier League matches and collected his first winners' medal when Chelsea won the FA Cup. Although not featuring in the final, he made four appearances in earlier rounds.
The season would culminate in a UEFA Champions League Final against Bayern Munich, as Chelsea, now under the management of Roberto Di Matteo, tried to win the illustrious competition for the very first time.
Incredibly, Bertrand made his debut in the competition showpiece, the first player to do so, as Chelsea dramatically triumphed on penalties.
That summer was also a whirlwind one for Bertrand. His inclusion in the Team GB squad for the 2012 Olympics in London involved three tournament appearances and was followed by his first senior international call-up.
A part of several youth age groups for his national side, he made his senior bow as a substitute against Italy, in a 2-1 win. He has since won 19 caps for his country, scoring once, and was part of the England squad for UEFA EURO 2016.
The start of 2012/13, meanwhile, brought Bertrand’s first senior Chelsea goal, in the FA Community Shield against Manchester City and then a 50th appearance for the Blues in April 2013, as well as a starting berth in the FA Cup Semi-Final.
Having played in the UEFA Super Cup and Champions League, Chelsea then dropped into the UEFA Europa League, where Bertrand played five times on the way to lifting the trophy under Rafa Benítez.
Finding first team opportunities limited, another loan spell in the second half of the 2013/14 campaign, this time with Aston Villa, added further experience to Bertrand’s growing reputation as an attacking left-back with plenty of pace and crossing ability.
The following season saw Southampton take the defender to St. Mary’s Stadium, and by February, so impressed were the South Coast outfit with his performances, they made the move a permanent one.
The England international would enjoy one of the best seasons of his career as he was named in the PFA Team of the Year after two goals and three assists in 34 Premier League games.
And 2015/16 was similarly productive with one goal and four assists for the marauding full-back as he consistently performed for an impressive Saints side who achieved three consecutive top-eight finishes in the top-flight.
Europa League football arrived in 2016/17 as Southampton narrowly missed out on qualification for the knockout stages and while the final four seasons of his Southampton career all ended with bottom half finishes, he has nevertheless been a shining light in both defensive and attacking areas.
In 2017/18, Bertrand made another 35 Premier League appearances, while he played in every FA Cup tie on the Saints' run to the semi-finals of the competition.
And the following season, his only goal came against Leicester, though it was the Foxes who triumphed 2-1 at St. Mary's Stadium in August 2018.
The full-back's next strike was in December 2019, in a 2-1 home win over Norwich City, before ending the campaign six games unbeaten, including four victories.
For the second time in three seasons, Southampton reached the FA Cup Semi-Finals, narrowly defeated by eventual winners Leicester City in the last four at Wembley Stadium, which was Bertrand's fourth appearance in the 2020/21 competition.
His career at Southampton totalled 240 appearances, eight goals and 20 assists. While he will no doubt look back fondly on his time with the club, Bertrand is now ready to take the next step in his career, with Leicester City.