Cijntje attended Champagnat Catholic High School in Florida. In 81 innings of work throughout his high school career, Cijntje recorded a 2.32 ERA and allowed 39 hits, 39 runs while also walking 31 batters. He had a 7-6 record but struck out 166 batters and recorded a 0.86 WHIP average. He was ranked the no. 34 pitcher in the nation and the no. 9 prospect in Florida. Cijntje joined Mississippi State following his high school career.
Last year as a freshman, Cijntje made 14 appearances, 13 of them starts. He struggled a bit, posting a 3-5 record with an 8.10 ERA. He struck out 63 batters and walked 34 in 50.0 innings pitched.
This year is Cijntje's sophomore season. He will be draft eligible and is expected to be one of Mississippi State's starters once again. He hopes to take a step forward this year and improve his draft stock.