Daily Bagel: Djokovic chases the only Masters 1000 title that's eluded him

Novak Djokovic chases Masters 1000 title in Cincinnati, Vicky Duval, the concern for mental health problems in tennis and more of the interesting reporting, writing and quipping from around the Internet.

The Daily Bagel is your dose of the interesting reporting, writing and quipping from around the Internet.

• This week at the Western and Southern Open, Novak Djokovic is chasing the only ATP Masters 1000 tournament title that's eluded him.

• The whiff of a changing tennis world, from Damien Cox for Sportsnet.ca, on what the tennis world will be like after the Big Four.

• Jack Sock is taking over the U.S. Open Series Instagram on Tuesday. 

#https://instagram.com/p/6hzXBBlU1m

• Relive Serena and Venus Williams's 2008 doubles Gold medal at the Beijing Olympics.

• From Forbes: 5 stats you need to know about the 2015 U.S. Open.

• From Mathieu Vendette, a volunteer ballboy for five years, filmed his last tournament on the job with a GoPro. Watch the video for an interesting look at the life of a ball boy at the Rogers Cup in Montreal:

[youtube=https://www.youtube.com/watch?v=wAXAEvDFAN4​]

• Bryan Armen Graham for The Guardiandetails Vicky Duval's first match in 14 months, her road back to professional tennis after cancer and her goals for the this month's U.S. Open in New York.

• Mardy Fish likes Waffle House:

[tweet=https://twitter.com/MardyFish/status/633652382472257536] 

• Simon Chambers for ESPN writes about the growing concern for mental illness on the tennis tour. Is tennis more vulnerable to mental health problems than other professional sports? 

• ICYMI: Belinda Bencic's reaction after she was told she was eligible for a $1 million bonus: