The Canadian Football League’s regular season kicks off Thursday with the Hamilton Tiger-Cats playing the Toronto Argonauts at BMO Field in Toronto (7:30 p.m. ET, ESPNews/WatchESPN).
Below, ESPN’s Stats & Info Group looks at the most notable NFL players who had ties to the CFL, beginning with those whose CFL performance was a springboard to an NFL career.
QB Warren Moon: Moon started his professional career with the Edmonton Eskimos, playing in the CFL from 1978-83. He helped the Eskimos win five Grey Cups, throwing for 21,228 yards in the CFL.
Moon joined the Houston Oilers in 1984 and played 17 NFL seasons for four teams, totaling more than 70,000 pass yards as a pro (CFL and NFL). He was inducted into the Pro Football Hall of Fame in 2006.
QB Joe Theismann: Theismann was drafted out of Notre Dame by the Miami Dolphins in 1971 but decided to head north, playing three seasons for the Toronto Argonauts from 1971-73. He was a CFL All-Star in 1971 and 1973 before joining the Washington Redskins in 1974.
Theismann spent 12 seasons with Washington, helping lead the team to a win in Super Bowl XVII and winning the 1983 AP MVP award.
QB Doug Flutie: The 1984 Heisman Trophy winner, Flutie was selected in the 11th round of the 1985 NFL draft. He played for the Chicago Bears and New England Patriots from 1986-89 before joining the BC Lions of the CFL.
He spent the next eight seasons playing in Canada, winning the CFL Most Outstanding Player award six times and the Grey Cup three times. Flutie returned to the NFL in 1998, starting 52 games for the Buffalo Bills and San Diego Chargers over the next seven seasons.
Flutie was named the No. 1 player in CFL history by a TSN poll in 2006.
QB Jeff Garcia: Garcia signed with the Calgary Stampeders in 1994, beginning his CFL career as Flutie’s backup. He threw for more than 16,000 yards in the CFL and was named the MVP of the Stampeders’ win in the 1998 Grey Cup.
Garcia joined the San Francisco 49ers in 1999 and started all 16 games for the team each year from 2000-02. He was a four-time Pro Bowl selection, throwing for more than 25,000 yards and 161 touchdowns in his NFL career.
DE Cameron Wake: Wake was undrafted out of Penn State and signed with the BC Lions in 2007. He had 16 sacks as a rookie and was named the CFL Rookie of the Year. Wake followed that season with 23 sacks in 2008.
In 2009, Wake joined the Dolphins, and in 2010 he had 14 sacks, the third-most in the league. He signed a two-year extension with the Dolphins in May.
CB Brandon Browner: Browner signed with the Denver Broncos as an undrafted free agent from Oregon State in 2005 but never appeared in a game, instead beginning his professional career with the Stampeders.
Browner played in the CFL from 2007-10, was a three-time All-Star and won the 2008 Grey Cup with Calgary. Browner signed with the Seattle Seahawks in 2011, reaching the Pro Bowl in his first full NFL season. He was a starter for the Patriots in Super Bowl XLIX.
WR Joe Horn: Horn played the 1995 season with the Memphis Mad Dogs, part of the CFL’s attempt to expand to the United States. He had more than 1,000 receiving yards in his only CFL season before getting taken by the Kansas City Chiefs in the fifth round of the 1996 NFL draft.
Horn spent four seasons in Kansas City but has had his most NFL success with the New Orleans Saints, reaching four Pro Bowls and finishing with four 1,000-yard seasons.
For some other notable NFL stars, the CFL was a minor footnote to their careers.
WR Fred Biletnikoff: Biletnikoff spent his entire 14-year NFL career with the Oakland Raiders, averaging more than 15 yards per reception and leading the NFL with 35 touchdown catches from 1969-72. His final NFL season was in 1978, but he spent one season with the Montreal Alouettes in 1980, catching four touchdowns. Biletnikoff was inducted into the Pro Football Hall of Fame in 1988.
RB Ricky Williams: Williams won the 1998 Heisman Trophy and was the fifth pick in the 1999 NFL draft. He led the NFL with a Dolphins single-season record 1,853 rushing yards in 2002 before retiring in 2004.
After returning to the NFL in 2005, Williams was suspended for the 2006 season. He played for the Argonauts in 2006, rushing for 526 yards in his only season in Canada. Williams returned to the NFL in 2007 and played five more seasons for the Dolphins and Baltimore Ravens.
WR Chad Johnson: Johnson was a second-round pick by the Cincinnati Bengals out of Oregon State in the 2001 NFL draft, and he had at least 1,000 receiving yards in six of his first seven seasons, including an NFL-best 1,369 yards in 2006.
The six-time Pro Bowl selection had the second-most receiving yards in the league from 2002 through 2007. His last NFL season was with the Patriots in 2011, and he played the 2014 season in the CFL with the Alouettes.
DE Mark Gastineau: Gastineau was a second-round pick in the 1979 NFL draft and spent his entire 10-year career with the New York Jets. He was a three-time first-team All-Pro and had 54.5 sacks from 1983-85, 11 more than any other player. His 22.0 sacks in 1984 are tied for the second-most since the stat became official in 1982.
Gastineau tried a comeback with the BC Lions in 1990 but lasted just four games before an injury led to his release.