Marshall played for fourteen seasons in the National Rugby League for Sydney club Wests Tigers, with whom he won the 2005 NRL Premiership.

Blossoming into one of rugby league's superstars en route to the Wests Tigers' maiden premiership (2005) In 2005, Marshall injured his other shoulder in the opening minutes of the first trial match.

-Wayne Bennett[24]Marshall made his comeback from surgery against St George Illawarra in round 1, but broke his cheek bone.

Marshall had to adapt to changes within the team such as the departure of halfback, Scott Prince, and the added responsibility of goal kicking while fullback, Brett Hodgson, was recovering from a knee injury.

Rugby League World Cup victory (2008) In 2008 Marshall's injury troubles continued when he suffered a knee ligament tear in the third minute of the season's opening game.

[33] Bestowed upon the captaincy of the Kiwis' as one of the league's marquee talents (2009) In round one of the 2009 season, Marshall started at halfback alongside John Morris at five-eighth.

By the third round of the season, Marshall began to make an impact in his new role, helping the team to a 40–24 win over the Sydney Roosters.

[34] In March, despite speculation that he might play rugby union in Japan, Marshall signed with the Wests Tigers for a further two seasons through to the end of 2011.

[39] In March 2010, Marshall scored two tries against the Parramatta Eels to become the highest try-scorer for the Wests Tigers, breaking the record of 43 previously held by Daniel Fitzhenry.

Marshall lead the Kiwis to victory in the 2010 Four Nations tournament, setting up two late tries in what was described as, "perhaps the finest game of his life.

[43] Top pointscorer in the NRL; Dally M Five-Eighth of the Year (2011) As New Zealand captain, Marshall was again an automatic selection in the 2011 All Stars Match.

[46] Before the end of the season he had eclipsed Brett Hodgson as the highest scorer in the short history of the Wests Tigers, having amassed 797 points in 151 games.

On 3 November 2011, The annual RLIF Awards dinner was held at the Tower of London and Marshall was named stand-off half back of the year.

[52] In the penultimate game of the regular season, Marshall kicked two goals to become the first Wests Tigers and 43rd player in the Australian competition to score one thousand points.

[citation needed] Relegation to the bench as career form slumped (2013) As the incumbent New Zealand national captain, Marshall was again selected to play in the 2013 NRL All Stars game.

[58][59] He finished the remainder of the season before leaving, and left the Wests Tigers as the club's all-time top try and point scorer.

Blues coach Sir John Kirwan hinted that number 10 (first five-eighth), not 15 (fullback), may be Marshall's ideal position.

"[65] In February 2014, Marshall made his Super Rugby debut for the Blues against the Highlanders at Forsyth Barr Stadium in Dunedin coming on off the bench in the 59th minute playing at fullback which resulted in a re-shuffle with Charles Piutau shifting to the centres.

[66] On 15 March 2014, Marshall made his first appearance at fullback for the Blues for the clash against the South African team, the Lions at Ellis Park Stadium in Johannesburg.

The Dragons were defeated in golden point extra time by the Bulldogs in the first elimination final[72] with Marshall being forced from the field in the second half with an ankle injury.

[73] Marshall had been set to play game number 250 the weekend earlier against the Gold Coast Titans,[74] before a troublesome hamstring pushed it back a week.

Homecoming; slow but sure return to the Benji of the past (2018) Marshall signed a deal in August 2017 to go back to his first club The Wests Tigers for one year.

With the departure of Aaron Woods, Marshall was named as one of 5 co-captains at Wests Tigers, alongside Chris Lawrence, Elijah Taylor, Russell Packer and Josh Reynolds.

Named on the bench for his return in round 1, Marshall got a call-up to five-eighth after a late injury to Josh Reynolds, and was said to play a "central role" in the surprise victory over eventual premiers the Sydney Roosters.

"[81] With Reynolds suffering further injuries, Marshall made 21 appearances for the season as Wests' missed out on the finals, finishing in 9th position.

Veteran experience and subsequent return to the Kiwis' squad (2019) Marshall's contract renewal for 2019 was announced at the same time as long-time teammate Robbie Farah.

Marshall made 19 appearances for the Wests Tigers in the 2019 NRL season as the club finished ninth on the table and missed out on the finals.

[88] Farewell season; and one more opportunity at a premiership (2021) On 29 January, Marshall signed a one-year contract with the South Sydney Rabbitohs.

[95] In the 2022 Queen's Birthday and Platinum Jubilee Honours, Marshall was appointed a Companion of the New Zealand Order of Merit, for services to rugby league.

However due to the Tigers' poor 2023 season, the club mutually parted ways with Sheens in August, with Marshall moving into the head coach role a year earlier than expected.