He was sent by then-Bishop Jerome Listecki to the Pontifical North American College in Rome, Italy to continue his seminary studies. He attended the Pontifical University of St. Thomas Aquinas (the Angelicum) in Rome and graduated with a Baccalaureate of Sacred Theology (S.T.B.) in 2012 and a Diploma in Pastoral Theology with a specialization in Spiritual Theology in 2013. He was ordained a deacon at Saint Peter’s Basilica in the Vatican on October 4, 2012 by Archbishop John Myers of Newark, NJ.
Upon completion of his seminary studies, he was ordained a priest for the Diocese of La Crosse on June 22, 2013 at the Cathedral of St. Joseph the Workman in La Crosse by Bishop William P. Callahan, OFM Conv., bishop of La Crosse. His first assignment was as parochial vicar of St. James the Greater Parish in Eau Claire and chaplain at Regis Middle and High Schools in Eau Claire. In 2014, he was transferred to be parochial vicar of St. Mary’s Parish in Altoona and St. Raymond of Peñafort Parish in Brackett, while continuing as chaplain at Regis.
2016, Bishop Callahan asked him to study canon law at The Catholic
University of America in Washington, DC. He began studies there in
Summer 2016 while continuing in the parishes and at Regis. He was able
to move to Washington in May of 2017 and was there until August of
2019. He finished the Licentiate in Canon Law (J.C.L.) at the end of
August 2019 and was assigned as parochial administrator of St. Mary's Immaculate Conception Parish in Custer and Sacred Heart Parish in Polonia. In July 2020, Fr. Guanella was named pastor of St. Mary's and Sacred Heart parishes.