The 23-year-old has been one of Leverkusen's best players over the past year, and was recently rewarded with a call-up to Joachim Low's Germany squad.
Bender has represented Germany at every youth level from under-17's upwards, and the tough tackling midfielder made his debut for the full national side just over a year ago.
Bundesliga giants Bayern Munich were reportedly keen to bring Bender to the Allianz Arena during the summer transfer window, but Leverkusen rejected the approach. Leverkusen's sporting director Rudi Voeller made it clear he was not willing to entertain offers for the club's star players.
But now Manchester United are monitoring the Bundesliga ace, as Sir Alex Ferguson looks for options to strengthen his central midfield.
The United boss has Michael Carrick, Darren Fletcher, Anderson, Tom Cleverley and Paul Scholes in the middle of the park, but has long been linked with a big-money move for a new midfielder.
Bender, who began his career with 1860 Munich, could be the player he's after, and Ferguson has reportedly dispatched United scouts to track the Leverkusen star's progress.
The 23-year-old was named in Low's 23-man Germany squad for Euro 2012, scoring in their final group game against Denmark, his only international goal to date.
Bender can also fill in at right-back, but is most comfortable as a central midfielder, and United most likely have their eye on him in relation to potentially filling this role at Old Trafford.