Joined the Gloucester Rugby England Academy in the summer of 2002 at the age of 18. He has progressed through the U21 ranks and put in some good performances for the United side over the last two seasons, including a 70-metre try against London Irish in the Zurich ‘A’ League. With a number of players missing through international commitments Foster started a handful of games for Gloucester Rugby during the Six Nations last season.
Has re-established himself in Dean Ryan’s squad during pre-season with a series of excellent displays. Struggled to come to terms with the Premiership in the centre late last term, but has made real strides on the wing. Was outstanding at the Issoire tournament and scored a hat-trick during Gloucester Rugby’s pre-season victory over Calvisano.
Mark Joined Exeter in 2009, and was a regular in the Exeter side. Foster scored Exeter's first try in the Aviva Permiership against his former club Gloucester in Exeters first Premiership match. However he suffered an injury and was unable to make it back into the Chiefs first team following his recovery. Foster joined Jersey on loan on 27 February 2013 and on 13 May 2013 it was announced Foster will be joining Jersey on a two-year deal.