Born in
Willemstad, Netherlands Antilles, Agustien began his career in the youth system of Dutch club
Willem II. Agustien joined English
Championship club
Birmingham City in July 2008 on a season loan, with an option to make the deal permanent at the end of the
2008–09 season for a fee of €2 million. He made his first-team debut in the
League Cup defeat at
Southampton on 26 August 2008, and played his first match in
the Football League four days later in a 1–1 draw at
Norwich City. Having missed pre-season training because of a
hernia operation, he did not adapt immediately to the pace and physicality of English football. He played 20 games in all competitions, but the second half of his season was dogged by injury. Birmingham manager
Alex McLeish "couldn't commit [himself] to bringing him in for the money asked", so Agustien returned to AZ when his contract expired on 26 May 2009. After his return to AZ, he was loaned to
RKC Waalwijk, newly promoted to the Eredivisie, for the 2009–10 season. At the end of that season, he was released by AZ. Later he joined
Swansea City of the English Championship on trial, but sustained an injury in a pre-season match which delayed his signing. After passing what was described as a "tough" medical, Agustien signed a two-year contract with the Welsh club in October. He made his debut two weeks later, coming on for
Andrea Orlandi after 69 minutes as Swansea beat
Leicester City 2–0. By February 2011, Agustien was anxious for regular first-team football, and suggested that there had been interest from clubs in taking him on loan, but manager
Brendan Rodgers considered him part of the Swansea squad. Agustien signed on loan for
Crystal Palace on 8 March for the rest of the season. He made his debut against
Barnsley in a 2–1 victory for Palace. He made his Premier League debut for the newly promoted Swansea in a 4–0 loss against Manchester City, but suffered a hamstring injury in September, and was restricted to one brief substitute appearance in the next three months. In the 1–1 draw with
Queens Park Rangers at the end of December, Agustien started in central midfield, but following an injury to
Àngel Rangel he spent the second half at right back, a position he had never played before; he was named man of the match: Ankle surgery in early March revealed further problems that kept Agustien out for the remainder of the season. Rodgers confirmed that Agustien would be offered a contract extension despite his injuries, In the 2012–13 season was a big change for Swansea City, with change of management and new players. For Agustien, his injuries continued to haunt him, having missed five matches, due to an ankle injury. Ahead of the 2013–14 season, Agustien, along with
Alan Tate,
Luke Moore and
Leroy Lita, was left out of the squad for the pre-season tour, which led their future uncertain. During July 2013, Agustien transferred to Championship club
Brighton & Hove Albion signing a two-year contract, however the deal was delayed for a number of days whilst awaiting international clearance which was finally completed on 1 August. Agustien made his debut for Brighton during a pre-season friendly game against
Norwich City which finished 1–1. He made 14 appearances in all competitions in his first season, but only 3 in his second, which was disrupted by injury. He was released when his contract expired at the end of the 2014–15 season. On 25 September 2015, it was announced that Agustien had signed a contract with the
Danish 1st Division side
Vendsyssel FF until the end of the year. Wearing number 13, the player was struck by injuries and his contract was not extended when it expired on 1 January 2016. In March 2016 he signed for Scottish club
Hamilton Academical. In May 2016 it was announced that he would leave Hamilton at the end of the 2015–16 season. Agustien returned to Dutch football for 2016–17, signing a one-year contract with Eerste Divisie club
FC Dordrecht. He was released by the club on 15 November 2016. Following his release from the club, Agustien signed with
Filipino club
Global F.C., playing in the
Philippines Football League. Agustien signed for English
National League North club
Nuneaton Borough on 27 June 2018, but left again by mutual consent before the season started. He played for
Halesowen Town of the
Southern League on a non-contract basis, then trained with and appeared as an over-age player for
Birmingham City's under-23 team, before joining
National League club
Barrow on 15 November on a short-term contract. He scored twice from 11 appearances in all competitions, On 21 March 2019, Agustien signed for another National League club,
Wrexham, until the end of the season. He made three appearances before being released when his contract expired. He signed for
Bradford (Park Avenue) of the National League North in late September 2019, and went straight into the starting eleven for their visit to
Brackley Town. He was substituted after 57 minutes with his team down to ten men and losing 5–0; the final score was 8–0. On 30 January 2020 he signed for
Mickleover Sports. On 12 October 2022, Agustien returned to the National League North when he signed for
Kettering Town. On 2 December 2022, Agustien joined
Southern League Premier Division Central side
Hednesford Town. In June 2023, he joined Northern Premier League Premier Division club
Matlock Town, leaving the club in September 2023. He subsequently joined Southern League Premier Division Central club
Alvechurch. ==International career==