The nationally ranked Hawks enjoyed one of the best cross-country seasons in the history of their program, winning the Class A, Rhode Island and New England titles as well as the NXN Northeast Regional Championship, and Sienko led them every step of the way. The Class A champion with a time of 16:08.36 and the individual state champ, in 15:56.92, the senior went on to place placed 17th at the New England Championships in 16:43 and eighth at the NXN Northeast Regionals in 16:17. Earlier in the season, Sienko helped Hendricken capture first place at the 35th annual Manchester Nike Invitational Cross Country Classic in New Hampshire with his runner-up finish of 15:29, which is the third-fastest time ever run on the Derryfield Park course. He placed third (15:20) in the Great American Cross Country Festival’s Race of Champions in North Carolina, helping Hendricken to a third-place team finish there.

Making his first appearance on the All-State team, MacKenzie placed fifth (16:45) in helping Hendricken to the Class A Championship, then sixth in the State Championships (16:37). The senior went on to help his team secure its first New England Championship in seven years, finishing fifth among Rhode Island runners and 35th overall. His 28th-place finish (16:51) was a key to Hendricken winning the NXN Northeast Regional Championships, which qualified the Hawks for the Nike Cross Nationals in Portland, Ore., where they then placed 10th.

The 5-11, 240-pound senior was the mainstay of the Hendricken offensive and defensive lines. He helped open holes for Hendricken's explosive running game on offense and was involved in 90 tackles on defense, including six sacks.

The Division I scoring leader this season, the 5-7, 175-pound running back scored 22 touchdowns and rushed for 1,371 yards. His 132-point production on touchdowns and conversion rushes sparked a Hendricken comeback in which the Hawks rebounded from a 1-3 start to end up in the Division I Super Bowl.

The 5-7, 240-pound offensive and defensive lineman became a major player on the Hawks' defensive unit this season as he made 75 tackles and posted four sacks. He was especially effective during the Hawks late-season drive to the Division I Super Bowl.

One of the few underclassmen on the first-team All-State squad, his play at linebacker helped the Hawks win seven straight games leading up to a berth in the Division I Super Bowl. Included among his 92 tackles were seven sacks. He also had three interceptions.