In this season, he was named Clubman of the Year and led the team to the 2009 FA Trophy Final, in which York were beaten 2–0 by Stevenage Borough.

Parslow was replaced as captain by Michael Ingham during 2009–10, and was an unused substitute in York's 3–1 defeat by Oxford United in the 2010 Conference Premier play-off final.

[5] Having progressed through the club's centre of excellence he earned a three-year scholarship in May 2002,[6] which turned into a one-year professional contract on its conclusion.

[7] He made an appearance for Cardiff in a 1–0 defeat by Bangor City in the FAW Premier Cup on 25 January 2005 and was included in the first-team squad for the 2005–06 season.

[14][15] At different points during 2006–07 Parslow lost his place in the team to David McGurk, Jason Goodliffe and János Kovács, but started York's last seven fixtures, including both legs of the 2–1 aggregate defeat by Morecambe in the play-off semi-final.

[17] Parslow missed the start of 2007–08 with an ankle injury, making his first appearance in York's third match, a 1–1 draw away to Exeter City on 20 August 2007.

[24][25] He took over the captaincy when club captain Mark Greaves and vice-captain McGurk were out of the team, starting on 27 January 2009 for a 1–1 draw away to Altrincham.

[26][27][28] Having "led by example" after attaining the captaincy, he was voted by supporters as York's Clubman of the Year for 2008–09, being presented the award before their penultimate home match against Eastbourne Borough on 18 April 2009.

[36][37] He played in the team as a centre-back and right-back before losing his place to Ben Purkiss after picking up a foot injury in York's 2–1 away defeat to Forest Green Rovers on 6 March 2010,[38][39][40] with the captain's armband being handed to Michael Ingham.

[41] He made his return in York's 1–0 away defeat by Stevenage in the last league match of 2009–10 on 24 April 2010,[39] but was dropped to the bench for the play-off semi-final 1–0 victory at home to Luton Town.

[49] Parslow formed a central defensive partnership with Chris Smith, and manager Gary Mills praised him by calling him "outstanding".

[54] He appeared twice at right-back in the first two months of the season when Lanre Oyebanjo was absent, before falling behind Jon Challinor and Jamal Fyfield for a place in defence.

[55][56][57][58][59] Parslow was used mostly as a substitute from then before a run starting in central defence in late December 2011, before losing his place after the signing of Chris Doig in February 2012.

[78] However, he sustained knee ligament damage when colliding into advertising hoardings as he sliced an attempted clearance during York's 2–1 defeat away to Southend on 23 November 2013.

[75] In his absence, York reached the play-offs with a seventh-place finish in League Two,[82] although they were beaten 1–0 on aggregate by Fleetwood Town in the semi-final.

[83] Parslow returned to fitness ahead of 2014–15, but having failed to regain his place in the team signed for Conference Premier club Grimsby Town on a one-month loan on 18 September 2014.

[85][86] Having been an unused substitute for three matches after returning to York, Parslow rejoined Grimsby on loan until 4 January 2015 on 7 November 2014, and made his second debut for the club a day later in a 3–1 home defeat to Oxford in the FA Cup first round.

[88] He came on as a 74th-minute substitute for Gregor Robertson in the 2015 Conference Premier play-off final against Bristol Rovers at Wembley on 17 May 2015; following a 1–1 draw after extra time, Grimsby lost 5–3 in a penalty shoot-out.

[90] After a successful trial,[91] Parslow signed for newly relegated National League club Cheltenham Town on a one-year contract on 29 July 2015.

[92][93] He made his debut when starting a 1–1 away draw with Lincoln City on 8 August 2015, Cheltenham's first match of 2015–16,[94] and established himself at centre-back, forming a partnership with Aaron Downes.

[121] A utility player, his intelligence and commitment allowed him to play a number of positions, including right-back, left-back and defensive midfield.