Twenty-five years ago Wednesday, a seemingly invincible athlete of mythical proportion was felled by an unthinkable injury.

Bo Jackson, the supremely strong and swift Los Angeles Raiders running back, suffered a severe hip injury while playing in an AFC divisional playoff game against the Cincinnati Bengals on Jan. 13, 1991. The injury was later complicated by a condition called avascular necrosis, which impedes blood flow and destroys bone cells and cartilage. Although Jackson didn't know it at the time, his football career was over at age 28.

Jackson had previously won the 1985 Heisman Trophy at Auburn and starred as an outfielder for the Kansas City Royals. His ability to outrun and run over defenders was legendary on football fields, as was his hitting power and mighty throwing arm in baseball stadiums. He remains the only athlete to play in the MLB All-Star Game and be named to the NFL's Pro Bowl.

On the 25th anniversary of Jackson's last NFL game, we present 10 things to know about one of the greatest athletes of all time.

The game itself

It was the only playoff game of Jackson's NFL career, and the injury precluded him from his lone opportunity to play in the Pro Bowl. The fateful moment occurred early in the third quarter, when he was tackled by Bengals linebacker Kevin Walker after a 34-yard run. Jackson finished with six carries for 77 yards. The Raiders were leading 7-3 at the time and went on to win 20-10, thanks in large part to Marcus Allen's 140 rushing yards.

Despite fracturing and dislocating his left hip, Jackson thought he had only suffered a hip pointer. After the game, he told reporters he expected to play in the AFC Championship Game the next week. The Raiders were routed 51-3 by the Buffalo Bills in that game, a beatdown that claimed the No. 22 spot in ESPN.com's rankings of the worst blowouts in sports history. The Bengals had beaten the Houston Oilers in a wild-card matchup the previous week but haven't won a postseason game in the ensuing quarter-century.

Bo Jackson suffered a dislocated hip on this play in a playoff game on Jan. 13, 1991. Getty Images

Baseball comeback

The Royals didn't think Jackson would be able to play during the 1991 season and released him on March 18 of that year. But he found believers in the Chicago White Sox, who signed him 16 days later. Jackson lasted only 23 games that season, not including six games in the minors, and underwent hip replacement surgery the following spring.

After missing the entire 1992 MLB season, Jackson played in 85 games for the White Sox in 1993. He played 75 games in the strike-shortened 1994 season for the California Angels and announced his retirement the following spring. Although Jackson never regained his previous form, he batted .248 with a .457 slugging percentage, 32 home runs and 102 RBIs in 183 games during his three MLB seasons after the injury.

Royals over Buccaneers

Despite stating that he was seriously considering playing baseball professionally, Jackson was selected No. 1 overall by the Tampa Bay Buccaneers in the 1986 NFL draft.

Following his selection, Jackson offered little indication which sport he was leaning toward.

"I'm tickled to death to be the first player chosen," Jackson said. "Right now, I'm unemployed. Hopefully, by midsummer I'll have a steady job. ... I'm up in the clouds. In a month or two, the smoke will have cleared and I'll know what I'm going to do."

Said Buccaneers owner Hugh Culverhouse, "I'll take that gamble about whether he'll choose baseball or football. It's not a gamble as far as his talent is concerned. We're prepared to make him the top offer in the history of the draft. We have a goal to sign him. If it's a question of money, we'll win."

It wasn't a question of money. Jackson spurned the Bucs' four-year contract offer reportedly worth between $5 million and $7 million in favor of baseball. Jackson was ruled ineligible during his senior baseball season for accepting a plane trip from the Buccaneers to work out for the team. Afterward, he strongly suspected the team knowingly sabotaged his eligibility. At that point, there was no way Jackson was going to play for the Bucs, Auburn baseball coach Hal Baird later said.

Two weeks after being drafted by the Royals in June 1986, Jackson signed with the defending World Series champions for three years and just over $1 million.

In five seasons with the Royals, Jackson batted .250 with 109 home runs and 313 RBIs in 511 games. Jonathan Daniel/Getty Images

College years

Jackson enrolled at Auburn, which he chose over the University of Alabama, after graduating from McAdory High in Bessemer, Alabama, in 1982. Crimson Tide coach Bear Bryant supposedly gave Jackson no assurances about playing time as an underclassman and didn't even guarantee he would play on offense.

Jackson became Auburn's career rushing leader, racking up 4,303 yards in four seasons, and his name appears 194 times in the school's 2015 football media guide. He rushed for 1,786 yards and 17 touchdowns as a senior, averaging 6.4 yards per carry, and won the 1985 Heisman Trophy. He also attempted one pass that season. It fell incomplete.

In baseball, Jackson lettered three times. As a freshman, he hit .279 with four home runs and 13 RBIs in 26 games. He didn't play as a sophomore, instead focusing on track and field. He emerged as a junior, batting .401 with 17 homers and 43 RBIs in 42 games. He played only 21 games as a senior before being ruled ineligible.

Jackson also lettered in track as a freshman and sophomore, twice qualifying for the NCAA indoor nationals in the 60-yard dash. He returned to the classroom in 1990 and graduated from Auburn with a degree in family and child development in 1995.

Jackson won the 1985 Heisman Trophy despite being knocked out of two games early because of injuries. TSN Archives/Getty Images

Heisman Trophy

Jackson narrowly won the Heisman over Iowa quarterback Chuck Long, capturing the honor by a mere 45 voting points. Only the 2009 award, which went to Alabama running back Mark Ingram by 28 points over Stanford running back Toby Gerhart, was determined by a smaller margin.

Auburn benefited from four 200-yard games by Jackson that season. He rushed for 290 yards and four touchdowns against Southwest Louisiana, 205 yards and two TDs against Southern Mississippi, 240 yards and two TDs against Ole Miss, and 242 yards and one TD against Georgia Tech. He had two 76-yard runs and a 67-yarder that season, with all three going for TDs.

Jackson would be the first Heisman winner since Army's Pete Dawkins in 1958 not to pursue pro football the following year. Florida State's Charlie Ward, the 1993 winner, would subsequently choose the NBA over the NFL. In case you're wondering, Dawkins became a brigadier general and investment banker.

NFL draft

When Jackson was selected No. 1 overall by Tampa Bay in 1986, other notable first-round picks included Oklahoma defensive tackle Tony Casillas (No. 2, Falcons), Purdue quarterback Jim Everett (No. 3, Oilers), Ohio State running back Keith Byars (No. 10, Eagles) and Iowa quarterback Chuck Long (No. 12, Lions). The only Hall of Famer from the 1986 draft class is Charles Haley, who was picked in the fourth round by San Francisco.

Jackson was also a territorial selection of the USFL's Birmingham Stallions in '86, but that league was in dire financial straits after three seasons and folded before embarking on its fourth.

The Bucs lost their rights to Jackson prior to the 1987 draft, and the Raiders took a flier on him in the seventh round that year. It was a shrewd move. Raiders owner Al Davis was willing to pay Jackson a full-time salary to play part-time for his team, and the former Auburn star agreed to dust off his football cleats. The Raiders gave Jackson a five-year deal worth a reported $7.4 million, although $2.1 million was deferred. He fulfilled four seasons of the pact and was to receive an insurance settlement after the injury.

Notable first-round picks in 1987 included Miami quarterback Vinny Testaverde (No. 1, Buccaneers), Alabama linebacker Cornelius Bennett (No. 2, Colts), Purdue safety Rod Woodson (No. 10, Steelers) and Michigan quarterback Jim Harbaugh (No. 26, Bears). Woodson is the only Hall of Famer from the 1987 draft class.

Jackson was picked No. 1 overall in the 1986 NFL draft, but he might have already decided to play baseball instead. AP Photo/Richard Drew

MLB draft

Jackson was selected three times in baseball's amateur draft. He was a second-round pick of the New York Yankees in 1982 out of high school but declined a six-figure signing bonus. The Angels identified him in the 20th round of the 1985 draft, following his junior season at Auburn. Finally, the Royals took him in the fourth round in 1986.

After signing with the Royals, Jackson was immediately assigned to Double-A, where he hit .277 with seven homers and 25 RBIs for the Memphis Chicks. He was promoted to Kansas City in September and singled off future Hall of Famer Steve Carlton of the White Sox in his first at-bat. Jackson hit his first career home run in his seventh game, off Seattle's Mike Moore.

40-yard dash

Jackson ran the fastest 40-yard dash ever recorded at the NFL scouting combine, an unfathomable 4.12 at the Superdome in 1986. The feat, however, was measured by hand and almost certainly didn't factor in the reaction time of the person with the stopwatch. The NFL instead recognizes Chris Johnson as the fastest to run the 40 at the combine, with a 4.24 in 2008.

For what it's worth, Hall of Fame cornerback Darrell Green, a decorated sprinter at Texas A&I, once reportedly ran 4.09 at Washington's 1986 training camp and 4.2 at camp in 2000 when he was 40. Another Hall of Fame corner, Deion Sanders, was hand timed at 4.21 by NFL scouts at Florida State in 1988.

A lot of mathematical and anecdotal evidence suggests the 4.12 is too good to be true, but we think it's a lot more fun to believe the legend. (Never mind that football players seldom run 40 yards in a straight line during a game.)

Run, run, run

Jackson had the NFL's longest run from scrimmage in three of his four seasons with the Raiders. In 1987, it was his famed 91-yard bolt on Monday Night Football in Seattle -- the same game in which he flattened Seahawks linebacker Brian Bosworth at the goal line. In 1989, it was a 92-yard dash against the Bengals. In 1990, he had an 88-yard run against Cincinnati but was tackled by Bengals cornerback Rod Jones at the 1-yard line.

Brian Bosworth and Bo Jackson gave fans a game to remember on Monday Night Football in 1987. Harley Soltes/The Seattle Times.

Bo bikes for charity

Jackson began an annual charity bicycle ride, Bo Bikes Bama, in 2012. It came as a response to a deadly string of tornadoes in Alabama the previous year. The event has raised approximately $1 million for the Alabama Governor's Emergency Relief Fund, which supports construction of storm shelters and offers financial assistance to disaster victims.

ESPN's David Fleming caught up with Jackson at last year's event and documented the former Heisman winner's first meeting with Bosworth since trucking him on Monday Night Football. Click here to read the article.