Marshall appreciation.

WWhen the Broncos complete their acquisition for Joe Flacco on March 13, he will join a small group: Traded Super Bowl-winning quarterbacks.

Johnny Unitas, Ken Stabler, Jim Mcmahon, Joe Montana, Brett Favre and Flacco.

Unitas was 40 years old in 1973 and three seasons removed from winning the Super Bowl with Baltimore when he was traded to the San Diego Chargers. He went 1-3 as a starter (three touchdowns and seven interceptions) and retired.

Stabler was 35 in 1980 and four years removed from a Super Bowl win with Oakland when he was traded after a lengthy holdout to the Houston Oilers. He went 11-5 in his first year (13 touchdowns and 28 interceptions) and the Oilers qualified for the playoffs.

Mcmahon was 30 in 1989 and four years removed from a Super Bowl win when a dispute with Chicago ownership led to a training camp trade to the Chargers. He lasted one year in San Diego, going 4-7 (10 touchdowns and interceptions apiece).

Montana was 37 in 1993 and three years removed from his fourth Super Bowl win and had only played one game in 1991-92. The 49ers committed to Steve Young and traded Montana to the Chiefs for a package that included a first-round pick. Montana went 17-8 in the regular season (29 touchdowns and 16 interceptions) and 2-2 in the playoffs (six touchdowns and four interceptions). The Chiefs reached the AFC title game in Montana’s first year.

Favre was 39 in 2008 (12 years after his Super Bowl win) when he came out of retirement and was traded by Green Bay to the New York Jets. In one year for the Jets, Favre went 9-7 and threw 22 touchdowns and a league-high 22 interceptions. After flirting with retirement again, he signed with Minnesota and led the Vikings to the NFC title game in 2009.

Flacco turned 34 last month and is six years removed from his Super Bowl win.

Several Super Bowl-winning quarterbacks changed teams because they were released or allowed to leave in free agency, including Joe Namath (Jets to Rams), Jeff Hostetler (Giants to Raiders), Mark Rypien (Redskins to Browns), Kurt Warner (Rams to Giants), Trent Dilfer (Ravens to Seahawks), Brad Johnson (Buccaneers to Vikings) and Peyton Manning (Colts to Broncos).

The most successful of those moves was Manning, who played in two Super Bowls for the Broncos (1-1 record). Warner reached another Super Bowl, but not until he moved on to the Cardinals and lost to Pittsburgh.

A personal hat-tip to linebacker Brandon Marshall, whose six-year stay with the Broncos is likely over.

I covered Marshall in 2012 when he was a rookie in Jacksonville and bounced between the practice squad and active roster for a 2-14 team. Cut by the Jaguars after the 2013 preseason, he chose to sign with the Broncos’ practice squad instead of staying in Jacksonville, believing a fresh