From an Orthodox point of view, there are at least two problems with this and similar devotions:
1) Christ is One, undivided Hypostasis. This is basic Orthodox Christian Dogma.
Devotion to various parts of Christ's Body and Attributes such as: The Sacred Heart of Jesus, The Shoulder Wound of Jesus, The Divine Mercy, The Precious Blood etc. begin to create a bit of a theological problem. If we divide Christ into His various "parts" and venerate each "part" individually, are we dividing the Hypostasis of Christ?
2) These devotions are the result of "private revelations" to individuals. Assuming, for the moment, that these "revelations" are not a result of prelest, even if they are genuine, they are still private, and therefore not required to be believed as doctrine. The Roman Catholic Church also states this, yet, in it's praxis, the Roman Catholic Church says differently. The "Feast of the Sacred Heart of Jesus" is a Universal Feast on the Roman Catholic Paschalion- so while nobody is required to accept devotion to the Sacred Heart as a true revelation, every Roman Catholic who goes to Mass 19 days after Pentecost is required to attend a Mass in honour of the Sacred Heart of Jesus. Very confusing. If it's not a doctrine, why have a Universal Feast for it? Similarly, the nun who received the "revelations" of the Devotion to the Divine Mercy, Sr. Faustina, was canonized as a Saint of the Roman Catholic on 30th April 2000, and on the 23rd of may that year, the Roman Catholic Church, in accordance with one of these private Revelations of Sr. Faustina, declared the Second Sunday of Easter to be the "Feast of the Divine Mercy", again, imposing on the whole Roman Catholic Church, a devotion which was the result of a private revelation, and therefore shouldn't require assent of faith.