On September 25, Foster scored his first career OHL goal against Curtis Cruickshank of the Kingston Frontenacs in an 8–5 loss.

Foster appeared in all 68 games with Peterborough in the 1999–2000 season, as he recorded 6 goals and 24 points while earning 116 penalty minutes, the fourth highest total on the club.

Foster spent a majority of the 2002–03 season with the Wolves, where in 75 games, he scored 15 goals and 42 points, which were the highest total of any defenceman on the team.

Foster played in his first game with the Wild on November 19, 2005, where he scored his first two NHL goals against Tomáš Vokoun of the Nashville Predators in a 4–2 victory.

On April 11, 2007, he played in his first Stanley Cup playoff game, earning an assist in a 2–1 loss to the Anaheim Ducks.

He suffered the injury when Sharks centre Torrey Mitchell checked Foster into the bottom of the boards while attempting to prevent an icing call.

Foster had season-ending surgery to repair his broken left femur and missed the remainder of the season and the 2008 playoffs.

Foster earned his first point as a member of the Lightning on November 21, an assist on a goal by Martin St. Louis in a 3–1 loss to the Carolina Hurricanes.

The next game, on November 22, Foster scored his first goal with the Lightning, against Ondřej Pavelec of the Atlanta Thrashers in a 4–3 win.

On November 27, Foster had his second NHL career two-goal game, scoring twice against Henrik Lundqvist of the New York Rangers in a 5–1 victory.

In 71 games with Tampa Bay during the 2009–10 season, Foster scored 8 goals and a career-high 42 points, although the Lightning failed to reach the 2010 playoffs.

On October 21, he earned his first point as an Oiler, providing an assist on a goal by Aleš Hemský in a 4–2 loss to the Minnesota Wild.

In his ongoing effort to get the NHL to change its icing rule, on February 3, 2011, Foster told TSN that there were complications during his surgery to repair his broken femur.

Don Cherry of Hockey Night in Canada had also been lobbying for many years for a rule change and had been critical of the NHL for not transitioning to no-touch icing.

Foster finished the 2010–11 season with 8 goals and 14 assists for 22 points in 74 games played as Edmonton failed to make the 2011 playoffs.

Returning to the Ducks organization, Foster appeared in two games with the club's new AHL affiliate, the Syracuse Crunch, where he earned an assist.

He made his debut with Anaheim on October 23, 2011, against the Phoenix Coyotes, in which he scored a goal against Mike Smith in a 5–4 loss.

He earned his first point with the Flyers when he assisted on a goal by Sean Couturier in a 5–2 loss to the Buffalo Sabres on January 20.

In his short tenure with the Eagles, Foster recorded 8 points in 15 playoff games to help claim the championship.

On April 24, 2015, Foster opted to continue in Germany after signing a two-year contract with the Nürnberg Ice Tigers.

[12] Foster made his head coaching debut on September 20, 2018, as the Frontenacs lost to the Peterborough Petes by a score of 4–0.

The next night, on September 21, Foster earned his first career OHL victory as Kingston defeated the Oshawa Generals 5–2.

The Frontenacs saw some improvement during the 2019-20, as the club added underage forward Shane Wright to the team as he was granted exceptional status by the CHL.

Kingston finished in eighth place in the Eastern Conference, earning a playoff berth, however, the post-season was cancelled due to the 2020 coronavirus pandemic in North America.

Craig resides in Sherwood, Prince Edward Island, and coaches a Midget AAA girls hockey team.