The New York Giants will work out free-agent running backs Brandon Jacobs and Willis McGahee on Tuesday, a league source told ESPN NFL Insider Adam Schefter.

The Giants had planned to work out McGahee since Friday, according to the source.

Former New York Jets running back Joe McKnight also will work out for the Giants on Tuesday, sources confirmed to ESPN.

Jacobs tweeted about the workout on Monday.

I would like to take this time to thank all the fans who have been behind me all this time.. Ill go (cont) pic.twitter.com/d6Rfkxpqv0 — Brandon Jacobs (@gatorboyrb) September 9, 2013

Jacobs, 31, spent his first seven seasons with the Giants before struggling through an injury-plagued season with the San Francisco 49ers in 2012. San Francisco waived Jacobs in December after the outspoken veteran was suspended for the final three regular-season games reportedly because he used social media to complain about a lack of playing time.

McGahee, who will turn 32 next month, was released by the Denver Broncos in June following a productive 2012 season that was cut short by a significant knee injury. Despite not participating in Denver's voluntary offseason workouts, McGahee insisted that he had no physical restrictions when he was released.