A product of USA Hockey's National Team Development Program, Nieto spent two seasons with the Michigan-based Under-17 and Under-18 national teams, winning the World Under-18 title with the United States in 2008-09 and 2009-10.

A speedy, tenacious, two-way forward, he became the first California-born player to be selected by the San Jose Sharks when they picked the Long Beach product in the second round (No. 47) in the 2011 NHL Draft.

Nieto starred at Boston University, where he was a co-recipient of the Friends Albert Sidd Unsung Hero Award as a sophomore in 2011-12, after finishing second on the team in scoring (42 points). Nieto scored the game-winning goal in Game 2 of BU's Hockey East three-game quarterfinal series victory against New Hampshire. He also scored twice when the Terriers lost to Maine in the semifinals.

In 2012-13, Nieto led BU in goals (18) and was second in points (37) as the Terriers reached the Hockey East championship game. He turned pro at season's end and made his American Hockey League debut with Worcester April 2, 2013, getting an assist in the game against Bridgeport.

After scoring two goals and five points through two games for Worcester in 2013-14, Nieto was called up to the Sharks and quickly impressed. He made his NHL debut Oct. 3, 2013 against the Vancouver Canucks.

Five days later he scored his first NHL goal and had two assists against the New York Rangers. He had 10 goals and 24 points in 66 games and finished fourth among Sharks forwards with 46 blocked shots.

Nieto scored his first Stanley Cup Playoff goal April 22, 2014 against the Los Angeles Kings in Game 3 of the first-round series. He tied for third on the Sharks in playoff scoring with five points (two goals, three assists).

In 2014-15, Nieto was eighth on the Sharks in points (27) and ninth in both goals (10) and assists (17). He had a three-game point streak from Oct. 8-14, 2014.

Nieto played a key role as a checking forward and penalty-killer in 2015-16 as the Sharks advanced to the Stanley Cup Final for the first time. He was claimed off waivers by the Colorado Avalanche on Jan. 5, 2017, and played four seasons with the Avalanche before he returned to the Sharks as an unrestricted free agent Oct. 13, 2020. On Jan. 25, 2023, Nieto and defenseman Ryan Merkley were traded to Colorado forward Martin Kaut and defenseman Jacob MacDonald.

NOTES & TRANSACTIONS

• Claimed on waivers by Colorado from San Jose, January 5, 2017.
• Signed as a free agent by San Jose, October 13, 2020.
• Traded to Colorado with Ryan Merkley by San Jose for Martin Kaut and Jacob MacDonald, October 13, 2020.