29-year-old Westcarr originally joined Walsall in November last year on a short-term loan from then parent club Chesterfield, but following his release by The Spireites he joined The Saddlers on a permanent basis in late January.
The Nottingham born front man began his career at Nottingham Forest, and became the youngest player to ever play for them, aged 16. He went on to make 23 appearances in a Forest shirt, scoring once, before moving to Cambridge United in 2005.
He went on to make 31 appearances, and scored a total of eight goals for Cambridge before departing the Abbey Stadium for Kettering Town.
Westcarr spent two successful seasons at Kettering including finishing second in Blue Square Bet North, and losing in the promotion play-offs.
In his second season, he was played mostly as a winger, but as Kettering's striking situation got desperate, Westcarr was on hand to step-in, finishing the season as the club's top goalscorer, in a season that seen them win the league in April to clinch promotion to the Conference National.
Craig later joined Stevenage for a undisclosed fee, but was unable to make an impact for the club and ultimately returned to Kettering where he spent another season before joining Notts County in the summer of 2009.
Craig joined County on a one-year deal and signed for a further two-years following an impressive first campaign, which included winning League Two, however halfway through the contract and after making almost 90 first-team appearances he was sold to Chesterfield for an undisclosed fee.
Craig made 38 league appearances during his debut season for the Spireites and scored a goal during their 2012 Football League Trophy victory over Swindon Town.
Westcarr's second season was less successful, he began as a first choice striker however after a run of poor form was placed on the transfer list. He joined Walsall in November 2012 on a short-term loan, and after a spell of negotiation was released by the club in order to join The Saddlers on a permanent basis in late January.
Craig had rejected the clubs initial offer but after several meetings with Dean Smith an agreement has finally been reached.