San Francisco 49ers third round draft pick, running back Frank Gore participates in a seven-on-seven drill during minicamp at the team's Santa Clara, Calif. headquarters, Friday, May 6, 2005. (AP Photo/D. Ross Cameron)

Linebacker Hunter Hillenmyer #92 of the Chicago Bears tackles running back Frank Gore #21 of the San Francisco 49ers on November 13, 2005 at Soldier Field in Chicago, Illinois. The Bears defeated the 49ers 17-9. (AP Photo/David Stluka)

San Francisco 49ers running back Frank Gore (21) is brought down by Houston Texans' Seth Payne, middle, in this file photo from their NFL football game on Sunday, Jan. 1, 2006, in San Francisco. Gore took over as the 49ers' primary rusher when Kevin Barlow was traded last month, and the second-year pro has shown flashes of being the club's best breakaway back since Ricky Watters. (AP Photo/Marcio Jose Sanchez)

San Francisco 49ers running back Frank Gore (21) walks off the field after the 49ers lost to the San Diego Chargers, 28-19, during their NFL football game, Sunday, Oct. 15, 2006, in San Francisco. (AP Photo/Paul Sakuma)

San Francisco 49ers running back Frank Gore runs off the field at the end of a 20-14 win over the Seattle Seahawks in an NFL football game in San Francisco, Sunday, Nov. 19, 2006. (AP Photo/ Jeff Chiu)

San Francisco 49ers running back Frank Gore (21) scores during an NFL game against the Green Bay Packers, Dec. 10, 2006 in San Francisco. (AP Photo/Greg Trott)

San Francisco 49ers running back Frank Gore (21) heads downfield during an NFL game against the Green Bay Packers, Dec. 10, 2006 in San Francisco. (AP Photo/Greg Trott)

San Francisco 49ers running back Frank Gore (21) takes the field during an NFL game against the New Orleans Saints, Oct. 28, 2007 in San Francisco. (AP Photo/Greg Trott)

San Francisco 49ers running back Frank Gore jumps into the stands after a 23 yard touchdown reception against the Tampa Bay Buccaneers during the fourth quarter of an NFL football game in San Francisco, Sunday, Dec. 23, 2007. San Francisco won 21-19. (AP Photo/Marcio Jose Sanchez)

San Francisco 49ers running back Frank Gore (21) looks for room during an NFL game against the Tampa Bay Buccaneers, Dec. 23, 2007 in San Francisco. (AP Photo/Greg Trott)

San Francisco 49ers running back Frank Gore dives into the end zone for a touchdown past St. Louis Rams' Oshiomogho Atogwe in the first quarter of an NFL football game Sunday, Nov. 16, 2008, in San Francisco. (AP Photo/Tony Avelar)

FILE - In this march 20, 2009 file photo, San Francisco 49ers' Frank Gore looks on at the team's NFL football minicamp in Santa Clara, Calif. (AP Photo/George Nikitin)

San Francisco 49ers running back Frank Gore (21) smiles as he jogs off the field after pregame warmups during an NFL preseason football game against the San Diego Chargers, Friday, September 4, 2009 in San Diego, California. The Chargers won the game 26-7. (AP Photo/Paul Spinelli)

San Francisco 49ers running back Frank Gore (21) rests during an NFL game against the Seattle Seahawks, Sunday, Sept. 20, 2009 in San Francisco. The 49ers won the game, 23-10. (AP Photo/Greg Trott)

San Francisco 49ers running back Frank Gore (21) heads for an 80-yard touchdown during an NFL game against the Seattle Seahawks, Sept. 20, 2009 in San Francisco. The 49ers won the game, 23-10. (AP Photo/Greg Trott)

San Francisco 49ers' Frank Gore (21) before an NFL football game between the Chicago Bears and the San Francisco 49ers in San Francisco, Thursday, Nov. 12, 2009. (AP Photo/Marcio Jose Sanchez)

San Francisco 49ers running back Frank Gore (21) heads downfield during an NFL game against the Oakland Raiders, Sunday, Oct. 17, 2010 in San Francisco. The 49ers won the game, 17-9. (AP Photo/Greg Trott)

San Francisco 49ers running back Frank Gore (21) during the NFL regular season game between the Pittsburgh Steelers on Monday, Dec. 19, 2011 in San Francisco, Calif. (Ric Tapia/NFL)

San Francisco 49ers running back Frank Gore (21) takes the field during an NFL game against the Dallas Cowboys on Sunday, Sept. 18, 2011, in San Francisco. The Cowboys won the game, 27-24. (AP Photo/Greg Trott)

San Francisco 49ers running back Frank Gore tries to outrun Washington Redskins strong safety LaRon Landry in the first half of an NFL football game in Landover, Md., Sunday, Nov. 6, 2011. (AP Photo/Nick Wass)

San Francisco 49ers Frank Gore prepares to run onto the field prior to the NFC Championship NFL football game against the New York Giants Sunday, Jan. 22, 2012, in San Francisco. The Giants won in overtime, 20-17. (AP Photo/G. Newman Lowrance)

San Francisco 49ers running back Frank Gore #21 during the NFL preseason game between the Minnesota Vikings on Saturday Aug. 10, 2012 in San Francisco. (Ric Tapia/NFL)

EAST RUTHERFORD, NJ - OCTOBER 21: Running back Frank Gore #21 of the San Francisco 49ers runs with the football against the New York Giants at Giants Stadium on October 21, 2007 in East Rutherford, New Jersey. The Giants defeated the 49ers 33-15. (AP Photo/Scott Boehm)

ST. LOUIS - NOVEMBER 26: Running back Frank Gore #21 of the San Francisco 49ers runs with the football against the St. Louis Rams at the Edward Jones Dome November 26, 2006 in St. Louis, Missouri. The Rams beat the 49ers 20-17. (AP Photo/Scott Boehm)

San Francisco 49ers running back Frank Gore (21) on Sunday, September 11, 2005, in San Francisco, California. The 49ers defeated the Rams 28-25. (AP Photo/Al Golub)

Jumboron at Levi's Stadium congratulate San Francisco 49ers running back Frank Gore (21) after he surpassed 1,000 yards rushing on the season during an NFL game against the Arizona Cardinals at Levi's Stadium in Santa Clara, California on Sunday, December 28, 2014. The 49ers defeated the Cardinals 20-17 in Week 17. (AP Photo/Kevin Terrell)

June 11, 2015: Indianapolis Colts running back Frank Gore (23) catches a pass during the Indianapolis Colts Mini Camp at Indiana Farm Bureau Football Center in Indianapolis, IN. (Icon Sportswire via AP Images)

Indianapolis Colts running back Frank Gore makes a catch during an NFL football training camp, Wednesday, July 27, 2016, in Anderson, Ind. (AP Photo/Darron Cummings)

Indianapolis Colts' Frank Gore (23) runs past San Diego Chargers' Dwight Lowery (20) during the first half of an NFL football game, Sunday, Sept. 25, 2016, in Indianapolis. (AP Photo/AJ Mast, File)

Indianapolis Colts running back Frank Gore (23) before an NFL football game against the Oakland Raiders in Oakland, Calif., Saturday, Dec. 24, 2016. (AP Photo/Tony Avelar)

Indianapolis Colts' Frank Gore (23) runs out of the tackle of Jacksonville Jaguars' Johnathan Cyprien (37) during the first half of an NFL football game Sunday, Oct. 4, 2015, in Indianapolis. (AP Photo/Michael Conroy)

13 September 2015: Indianapolis Colts Running Back Frank Gore (23) [7741] in action during a game between the Indianapolis Colts and the Buffalo Bills at Ralph Wilson Stadium, in Orchard Park, NY. (Photo by Robin Alam/Icon Sportswire)

Oct 4, 2015; Indianapolis, IN, USA; Indianapolis Colts running back Frank Gore(23) runs the ball against the Jacksonville Jaguars in overtime at Lucas Oil Stadium. (Thomas J. Russo/USA TODAY)

Dec 20, 2015; Indianapolis, IN, USA; Indianapolis Colts running back Frank Gore (23) runs onto the field prior to the game against the Houston Texans at Lucas Oil Stadium. (Brian Spurlock/USA TODAY)

Sep 25, 2016; Indianapolis, IN, USA; Indianapolis Colts running back Frank Gore (23) is pursued by San Diego Chargers linebacker Denzel Perryman (52) at Lucas Oil Stadium. Indianapolis defeats San Diego 26-22. (Brian Spurlock/USA TODAY)

Dec 18, 2016; Minneapolis, MN, USA; Indianapolis Colts running back Frank Gore (23) against the Minnesota Vikings at U.S. Bank Stadium. The Colts defeated the Vikings 34-6. (Brace Hemmelgarn/USA TODAY)

Indianapolis Colts running back Frank Gore accepts the Art Rooney Sportsmanship Award as former player Charles Woodson looks on during the 6th annual NFL Honors award show at the Wortham Theater Center on Saturday, Feb. 4, 2017 in Houston. (Perry Knotts/NFL)

Frank Gore of the Indianapolis Colts poses backstage with the Art Rooney Sportsmanship award at the 6th annual NFL Honors at the Wortham Center on Saturday, Feb. 4, 2017, in Houston. (Photo by Peter Barreras/Invision for NFL/AP Images)

Indianapolis Colts running back Frank Gore poses with the Art Rooney Sportsmanship Award during the 6th annual NFL Honors award show at the Wortham Theater Center on Saturday, Feb. 4, 2017 in Houston. (Ben Liebenberg/NFL)