After signs that supporter unrest was turning on Murray, on 9 February 2006, two days before the crucial Old Firm match, it was announced that Alex McLeish would leave his position as manager at the end of the 2005-06 season, and on 11 March, it was confirmed that former Lyon manager Paul Le Guen would indeed succeed him at the end of the season.
Murray predicted a fruitful reign under Le Guen, describing his capture as "a massive moonbeam of success" for the club and promising, "we’ve got big plans." He announced that the Frenchman would be given significant funds with which to strengthen the squad, with Rangers having announced an arrangement with sports retailer JJB Sports.
Known for unearthing and nurturing young talent, Le Guen made an immediate splash in the transfer market signing South African Under 19 player Dean Furman from Chelsea, and youngsters William Stanger and Antoine Ponroy from Rennes. While allowing Ibrox favourite Alex Rae to move to a new career as player-manager of Dundee, he has also signed Libor Sionko and Karl Svensson. Rangers had been strongly linked with a host of other players and signed midfielder Jeremy Clement from Lyon and goalkeeper Lionel Letizi from Paris St Germain as a replacement for the departing Ronald Waterreus. Senegal's World Cup 2002 midfield player Makhtar N'Diaye signed a one year contract after a short trial period with the club
Rangers' first match under Le Guen was a friendly against Irish Premier League champions Linfield on 6 July 2006 at Windsor Park, Belfast. Rangers won 2-0 with first half goals from Kris Boyd and Thomas Buffel. The squad flew out to South Africa on July 9 for a training camp where they played three matches, the first of which was a comfortable 4-0 win over local opposition with Charlie Adam netting a hat-trick. Rangers also defeated Jomo Cosmos 2-0 but, with a largely depleted starting line-up, they lost their final match 2-0 against Premier Soccer League champions Mamelodi Sundowns. Defender Fernando Ricksen did not take any part in the pre-season tour of South Africa due to what was described by the club as "unacceptable behaviour" on the flight to Johannesburg. Rangers returned to face English Premier League sides Middlesbrough and Bolton Wanderers where they won 1-0 and drew 1-1 respectively. The SPL opening day on July 30 proved fruitful for Paul Le Guen and Rangers as they defeated Motherwell 2-1 at Fir Park, thanks to an early strike from Libor Sionko and the winning header from Dado Prso. In Le Guen's first competitive game at Ibrox, Rangers were held to a 2-2 draw by Dundee United, and were forced to come back from 2 goals down.
On August 9, Fernando Ricksen went to Russian Premier League club Zenit St Petersburg, the new club of ex-Rangers manager Dick Advocaat, on a season-long loan. In return, a friendly was scheduled between the teams at Ibrox on August 23. On August 11 Rangers signed Manchester United's 19 year old winger Lee R. Martin on loan for a season. Rangers also recruited the services of Austrian Vienna defender Saša Papac while Marvin Andrews, Olivier Bernard, Robert Malcolm and Hamed Namouchi all departed.
By mid November, Rangers found themselves in third place, a full 15 points behind leaders Celtic. Sporadic wins were mixed with regular dropped points as the team struggled to find consistency in the early part of the season. Rangers did, however, start promisingly in the UEFA Cup, going on to become the first Scottish club to qualify from the UEFA Cup group stage in its three year history. Domestic results and performances, however, continued to be inconsistent and in January 2006, Le Guen controversially stripped midfielder Barry Ferguson of the captaincy.
On January 4 2007 Paul Le Guen left Rangers by mutual consent. This made him the club's shortest-serving manager, and the only one to leave the club without completing a full season in charge.