2010-11: Philippe Desrosiers played for the College Antoine-Girouard Gaulois midget AAA team in Quebec and won a silver medal with Team Quebec in the 2011 Canada Winter Games. Sharing the goaltending with Philippe Cadorette, he was 10-9 with a 3.54 goals against and .885 save percentage. Desrosiers was 2-3 in the playoffs with a 2.45 goals against and .907 save percentage. Desrosiers played two games at the CWG and had a 3.71 goals against and .837 save percentage. He was selected by the Rimouski Oceanic in the second round (29th overall) of the 2011 QMJHL Entry Draft.
2011-12: Desrosiers made his QMJHL debut, playing in three games for Rimouski, and played midget AAA hockey for College Antoine-Girouard. He was 1-2 in his brief stint with the Oceanic and had a 3.48 goals against and .899 save percentage. In 23 games for College Antoine-Girouard he was 16-4 with a 2.77 goals against and .907 save percentage. The Gaulois reached the Quebec midget AAA semifinals and in 11 playoff games Desrosiers was 6-3 with a 2.58 goals against and .905 save percentage.
2012-13: Desrosiers played 43 games for Rimouski in his first QMJHL season and was in net for Canada’s gold medal team at the 2013 U18 World Junior Championship. He was 22-8-5 with a 3.07 goals against and .900 save percentage for the Oceanic. Rimouski finished second in the East Division. Desrosiers played four games in the Oceanic’s six game playoff series with Gatineau and was 2-2 with a 2.26 goals against and .892 save percentage. At the U18 WJC in Sochi he was 5-0, including a 33-save effort in the gold medal game win over the USA; finishing with a 0.80 goals against and .970 save percentage. Desrosiers was ranked seventh amongst North American goaltenders in Central Scouting’s final rankings prior to the 2013 NHL Draft.
2013-14: Desrosiers attended camp with the Stars before returning to Rimouski for his second QMJHL season. He had the league’s fourth-best goals against (2.65); appearing in 52 of 68 games for the Oceanic. Desrosiers was 31-14-7 with seven shutouts and had a .907 save percentage. In February he set a QMJHL record by not allowing a goal in 213:15 minutes. Rimouski finished second in the East Division and reached the second round in the playoffs. Desrosiers was 7-3 in the playoffs, including two shutouts, and had a 2.34 goals against and .917 save percentage. He signed a three-year entry-level contract with Dallas in April 2014.
2014-15: Desrosiers attended training camp with the Stars before being returned to Rimouski for the 2014-15 season. Handling the bulk of the goaltending on an Oceanic team that had the league’s best record, he was named the CHL Goaltender of the Year. In 49 regular season games he was 29-9-3 with five shutouts and had a 2.50 goals against and .901 save percentage. Rimouski finished first in the East and defeated Memorial Cup host Quebec in the QMJHL finals, with both teams advancing to the tournament. Struggling and briefly supplanted by Louis-Philip Guindon during the playoffs, Desrosiers had a game for the ages in the dramatic Game 7 against Quebec in the President’s Cup final, stopping 47 of 48 shots in a 2-1 double overtime win. In nine QMJHL playoff games he was 5-3-0 with a 2.48 goals against and .910 save percentage. In four games at the Memorial Cup he was 1-2, with his only win coming in a 4-0 shutout of the host Remparts. He finished the tournament with a 3.23 goals against and .899 save percentage.
Desrosiers is an aggressive, confident butterfly goaltender that has a surprising amount of athleticism and quickness. He can get out of his butterfly stance just as quickly as he can get into it. He anticipates the play well and challenges adeptly with advanced rebound control at his age. Desrosiers understands the concept of directing rebounds, actively makes saves rather than just blocking shots. He moves well in the crease, mainly because he doesn't give up his leverage to push across entirely. Desrosiers is an active player. High shots can be problematic for him and he still has some holes to fill in his game.
Desrosiers has shown steady prospect in his first pro season as a 20-year-old in 2015-16. After starting the season in the ECHL with Idaho before being recalled to the AHL's Texas Stars in January, he won three of his first five AHL starts and was pushing starter Maxime Lagace for the starting spot. The career path of any young goalie is hard to predict but Desrosiers has the physical ability, size, and durability to suggest he can be an NHL starter.