Considering his successful junior career, perhaps it shouldn't have been surprising that Tierney would end up playing in the Stanley Cup Final during his first full season in the NHL.

A strong faceoff man and solid defensive player, Tierney played in three straight Memorial Cup tournaments with London of the Ontario Hockey League from 2012-14. Tierney was selected by the San Jose Sharks in the second round (No. 55) in the 2012 NHL Draft after helping London win the OHL title and reach the Memorial Cup final.

In 2012-13, Tierney finished fifth on London in points with 57. He then had 21 points in 21 playoff games as London won its second straight OHL crown, and had three points in five Memorial Cup games.

Tierney was voted the smartest player in the OHL's Western Conference in a poll of league coaches following the 2013-14 season. As captain that season, he led London with 40 goals and was second with 89 points, and was first on the team in playoff scoring with 17 points. He was selected to represent the OHL in the Subway Super Series tournament.

Tierney made his NHL debut with the Sharks on Oct. 8, 2014 against the Los Angeles Kings, getting an assist for his first NHL point. He would play 43 games with the Sharks and 29 with Worcester of the American Hockey League that season. He scored his first NHL goal, had an assist and was plus-two Feb. 5, 2015 against the Vancouver Canucks and had a three-game point streak with San Jose from March 23-28, 2015. Tierney had six goals and 19 points in his final 28 games of the season, leading Sharks rookies with 15 assists and finishing second among San Jose's first-year players with 21 points.

Moving into a third-line center role with the Sharks in 2015-16, Tierney played 79 games and proved capable of matching up with some of the NHL's top centers. He had five goals and nine points in 24 playoff games, including two goals in Game 2 of the second round against the Nashville Predators, as the Sharks advanced to the Stanley Cup Final for the first time.