Many well-known players in NFL history played their entire careers with one franchise, but circumstances have regularly sent stars to different teams.

Every so often, it works out.

But in several cases, a desperate team took a final shot on a former star. Instead of extracting the last of his production, the franchise soon realized the glory days had officially passed. And in others, a one-time star basically just stunk.

While unsuccessful tenures hardly diminish the shine of sterling careers, they are still memorable footnotes. 

Johnny Unitas, QB, Colts to Chargers

During the 1970 season, Johnny Unitas played a central role in the Baltimore Colts' Super Bowl win. However, he split snaps with Earl Morrall in 1971 and found himself benched for Marty Domres when the Colts started 1-4 in 1972.

Baltimore traded Unitas to the San Diego Chargers, and he tossed seven interceptions in four starts (three defeats).

San Diego also handed four starts to Wayne Clark and six to then-rookie Dan Fouts—a future Hall of Famer. The Chargers lumbered to a 2-11-1 record, and Unitas retired that offseason.

Franco Harris, RB, Steelers to Seahawks

Best remembered for the Immaculate Reception in the 1972 AFC divisional round, Franco Harris enjoyed 12 terrific years on the Pittsburgh Steelers. Through the 1983 season, he ranked No. 2 in NFL history with 11,950 career rushing yards.

Harris split with Pittsburgh, however, when contract negotiations soured. He later signed with the Seattle Seahawks, who lost running back Curt Warner to a knee injury in the 1984 opener.

Although the Seahawks went 6-2 in Harris' eight appearances, he mustered just 170 yards on 68 carries for a dismal 2.5 yard-per-rush average. Seattle cut Harris, and he soon retired.

Joe Namath, QB, Jets to Rams

Nearly a decade removed from an incredible Super Bowl win, Joe Namath left the New York Jets for the Los Angeles Rams.

The simple truth is that Namath hadn't played well in a long time. During his final two seasons with the Jets, he posted a 4-17 record and tossed 44 interceptions compared to 19 touchdowns. Nevertheless, the Rams took a chance on the future Hall of Famer.

Broadway Joe struggled in Hollywood.

"I really felt like I could still play even though I lost a lot of the physical skill that I was able to play with earlier," he said, per ESPN's Rich Cimini. But the results—five interceptions and four appearances prior to getting benched—tell a different story.

Cris Carter, WR, Vikings to Dolphins

After the Philadelphia Eagles released him prior to the 1990 regular season, Cris Carter turned around his personal life and became a professional star on the Minnesota Vikings. Over 12 seasons in Minnesota, he racked up 1,004 catches for 12,383 yards and 110 touchdowns.

Carter ultimately retired prior to the 2002 campaign, but injuries to Chris Chambers and Oronde Gadsden compelled the Miami Dolphins to pull the future Hall of Famer back to the field.

Years later, Carter regretted the decision.

"I had no business playing that season," he said in 2018, according to Jarrett Bell of USA Today.

Carter made a handful of appearances for Miami, finishing with eight receptions for 66 yards and a touchdown. He also missed several games because of a kidney abnormality.

Eddie George, RB, Titans to Cowboys

Though his career is not a model of efficiency, Eddie George topped the 1,000-yard rushing mark in seven of his eight seasons with the Houston Oilers/Tennessee Titans.

Understandably, George didn't agree to a pay cut after the 2003 season. However, that resulted in his release, and the Dallas Cowboys scooped up the four-time Pro Bowler to pair with second-round draft pick Julius Jones.

George occupied the lead role when an injury sidelined Jones. George managed just 324 yards in seven games without Jones, who returned and racked up 803 yards in the last seven contests.

Brett Favre, QB, Packers to Jets

Although the Green Bay Packers legend ended his career on a higher note with the Vikings—still an odd combination—Brett Favre's initial switch went poorly.

Following the 2007 season, Favre decided to retire. He soon reversed course, but the Packers had already moved into the Aaron Rodgers era and wouldn't give Favre his old job. Green Bay traded him to the New York Jets.

The Jets surged to an 8-3 start, but they collapsed down the stretch as Favre tossed an NFL-worst 22 interceptions. New York missed the playoffs, and Favre retired again.

He unretired again for Minnesota and reached an NFC championship in the first of his two seasons with the Vikings.

Chad Johnson, WR, Bengals to Patriots

"Ochocinco" played for the Cincinnati Bengals from 2001 to '10, earning two first-team All-Pro honors and six Pro Bowl trips. He amassed 10,783 receiving yards—the 27th-most in NFL history through 2010—and is, at the least, on the borderline of great.

Just forget about his season on the New England Patriots.

One social media post accurately sums up Chad Johnson's rough tenure. When replying to a message from someone who came to his profile for a laugh, he responded, "Look at my stats with the Patriots."     

New England won the AFC, but Johnson didn't contribute much. In 17 total games, he managed 16 catches.

Donovan McNabb, QB, Eagles to Washington

Donovan McNabb ended his Philadelphia Eagles tenure as the franchise's all-time leader in passing yards (32,873) and touchdowns (216). They traded him to NFC East rival Washington, and that unexpected marriage lasted one ugly 2010 season.

Washington trudged to a 5-8 record with McNabb as the starter, and he threw more interceptions (15) than touchdowns (14).

The following offseason, Washington dealt him to the Vikings—who benched him after a 1-5 start in favor of Christian Ponder. That didn't work out either, and McNabb never played another game.