After beginning his career on the island of Jersey for St. Clement and Trinity, Guthrie moved to England to sign for Accrington Stanley in 2011 making his professional debut the same year. He was sent out on loan to Conference Premier side Southport between November 2011 and January 2012 before moving to Bath City in the summer of 2012. After five goals in nine league appearances, he signed for Welling United, with whom he spent two seasons before transferring to Forest Green Rovers. He spent two years playing for Forest Green, scoring 19 goals in 79 league games. He returned to the English Football League in July 2016 when he signed for Colchester United.
Guthrie has represented England C, scoring on his debut in March 2016.
Born in Jersey, Guthrie began playing local football with St. Clement Sports Club from the age of eight. He broke into the first-team in 2009, before transferring to Trinity in 2011.
After one season with Trinity, Accrington Stanley took Guthrie on a two-week trial, scoring against Premier League side Blackburn Rovers in his first pre-season friendly appearance for the club. He signed a one-year contract with the League Two side with the option of a further year on 19 July 2011.
He was handed his professional debut on the opening day of the 2011–12 season in a 0–0 away draw at Northampton Town on 6 August.
In November 2011, Guthrie was sent out on loan to Conference Premier side Southport until January 2012 in order to get more match experience. He made five appearances for Southport, scoring one goal before returning to Accrington.
After failing to establish himself in the Accrington first-team, Guthrie was released alongside three other players at the end of the season.
Guthrie signed a short-term deal with Conference South side Bath City on 16 August 2012. He made his club debut on 18 August as a substitute in their 1–1 away draw against Welling United, before scoring a hat-trick on his home debut three days later in a 3–1 win over Maidenhead United.
Guthrie made 13 appearances in all competitions, scoring six goals before leaving the club after his short-term deal expired in October 2012.
Having previously been on trial with the club in the summer of 2012 following his release by Accrington, Welling United signed Guthrie after he left Bath City. He scored his first goals for Welling in April 2013, a hat-trick against Weston-super-Mare. He went on to tally eight goals in two seasons, amassing 61 appearances and helping the club to the Conference South title in his first season.
Forest Green Rovers signed Guthrie for an undisclosed fee from Welling in May 2014. He signed a two-year deal with Welling's Conference Premier rivals. He made his debut for the club as a substitute in a 2–1 win against Chester on 12 August 2014. His first start came on 11 October as he played the full 90-minutes for Forest Green in a 1–1 draw with Gateshead. He scored his first goal for the club in a 3–3 away draw against Torquay United on 15 November, before scoring his second of the match and the final goal of the game. He helped his side reach the Conference play-offs for the first time at the end of the 2014–15 season, appearing in the semi-final matches against Bristol Rovers where Forest Green bowed out 3–0 on aggregate. He had scored eight goals in 42 appearances in his first season for Forest Green.
Guthrie scored eleven goals in 45 appearances in his second season with the club as they reached the 2016 National League play-off Final at Wembley Stadium. He played for 77-minutes of the final, which Forest Green lost 3–1 to Grimsby Town on 15 May 2016.
Guthrie made a return to the English Football League in July 2016 when Colchester United signed him for an undisclosed fee. He agreed a two-year contract on 5 July and his signing was announced by Colchester on 6 July. He made his debut for the club on 6 August in Colchester's 1–1 draw with Hartlepool United at Victoria Park on the opening day of the season. He scored his first goal on 16 August in Colchester's 3–2 win over Grimsby Town. Guthrie scored his first professional hat-trick on 7 January 2017 in Colchester's 4–1 win at home to Carlisle United, and was subsequently named in the EFL 'Team of the Week'. He was nominated for the 'PFA Fans' Player of the Month' award for January but finished third behind Doncaster's John Marquis and Exeter's David Wheeler. He was ruled out for the remainder of the season in March 2017 after requiring surgery for an ankle injury picked up during Colchester's home game against Hartlepool United, having scored 12 goals in 36 games for the U's.
Guthrie was called up to an England C training camp for the first time in September 2015. On 22 March 2016, he made his England C debut in an away international against Ukraine. He started the match and scored the opening goal in a 2–0 victory.
He featured for Jersey at the 2011 Island Games, where his side earned a bronze medal.
Guthrie's older sister, Serena, is a member of the England netball team who featured in the 2014 Commonwealth Games and won a bronze medal at the 2011 World Netball Championships in Singapore.As of match played 25 February 2017.
with JerseyIsland Games bronze medal: 2011
with Welling UnitedConference South champions: 2012–13