Marino's golf game began to blossom at age 14, when he worked and played at the Army Navy Country Club in Fairfax; he graduated from W.T. Woodson High School in 1998. During his senior year he won the Virginia High School championship,
Marino embarked on his professional career in 2002 on the Tar Heel Tour, and moved to Florida to practice and play year-round. He qualified for the Canadian Tour for the 2003 season, and went to Canada again in 2004, but then headed back to Florida. There he played on the Golden Bear Tour, a developmental circuit backed by Jack Nicklaus in which all the events were within 60 miles (100 km) of West Palm Beach, near where he lived then (and now).[6]
Before reaching the PGA Tour, Marino won the 2006 Sidney Frank Memorial Gateway Tour Championship, where he carded a 13-under-par 59 during the third round.[7] It was his second Gateway Tour win of 2006.[8] Marino was a Monday qualifier on the Nationwide Tour in 2006, where he earned $134,000 and finished 42nd on the money list, which was insufficient to earn a PGA Tour card. Instead, he qualified through the six-round qualifying school in December, earning his card for the 2007 season.
In his rookie season of 2007, Marino finished 80th on the PGA Tour money list and retained his tour card for 2008, with winnings exceeding $1,100,000. He had four top-10 finishes in 31 events. In 2008, Marino finished 34th on the PGA Tour money list, earning over $2,000,000, and retained his tour card for 2009. He had six top-10 finishes in 32 events, highlighted by a career-best second-place finish in the Mayakoba Golf Classic at Riviera Maya-Cancun in Mexico.
Marino finished tied for second at the 2011 Sony Open in Hawaii.[10] He led the 2011 AT&T Pebble Beach National Pro-Am after the second and third rounds, but on the final day, eventual winner D. A. Points passed him. Marino had to make an eagle on the par-5 18th hole in order to tie Points, who had finished. But Marino hit into the Pacific Ocean and took a triple-bogey eight, which dropped him into a tie for fourth place.[11] Marino led the 2011 Arnold Palmer Invitational during the fourth round, as late as the 17th hole. But he suffered two buried lies in bunkers on the 15th and 17th holes, and despite making a birdie on the final hole, ended in second place, one stroke behind winner Martin Laird.[12] Marino advanced his position on the Official World Golf Ranking to a career high of #54.[13] Marino was identified as the best PGA Tour player without a victory by writer Craig Dolch, who noted that he has posted 21 top-10 finishes in his 124 Tour starts to date.[14]
In January 2012, Marino was diagnosed with a bone contusion on the tip of his tibia and femur in his left leg. He did not play again until May.[15] In 2012, he played at total of six PGA Tour events, making the cut in two of them. In 2013, he played in 12 PGA Tour events, making the cut five times.
In March 2016, Marino lost in a sudden-death playoff to Tony Finau at the Puerto Rico Open. In the playoff, both players birdied the 18th hole twice. But playing the 18th for the third time in the playoff, Marino three-putted from just off the green for a par, while Finau birdied the hole again for the win. This was Marino's fifth runner-up finish of his career but he is still winless in 182 events on the PGA Tour.
^CBS Sports broadcast of 2011 AT&T Pebble Beach National Pro-Am, 4th round, February 13, 2011; pgatour.com, 2011 AT&T Pebble Beach National Pro-Am tournament data
^NBC Sports broadcast of 2011 Arnold Palmer Invitational, 4th round, March 27, 2011; pgatour.com, 2011 Arnold Palmer Invitational tournament data
^pgatour.com, Official World Golf Ranking for March 28, 2011