The Catechism of the Council of Trent states:
Third Part of this Commandment
The third part of the Commandment comes next to be explained. It points out, to a certain extent, the manner in which we are to keep holy the Sabbath day, and explains particularly what we are forbidden to do on that day.
Thou shalt do no work on it, says the Lord, thou, nor thy son, nor thy daughter, nor thy man-servant, nor thy maid-servant, nor thy beast, nor the stranger that is within thy gates.
These words teach us, in the first place, to avoid whatever may interfere with the worship of God. Hence it is not difficult to perceive that all servile works are forbidden, not because they are improper or evil in themselves, but because they withdraw the attention from the worship of God, which is the great end of the Commandment.
The faithful should be still more careful to avoid sin, which not only withdraws the mind from the contemplation of divine things, but entirely alienates us from the love of God.
But whatever regards the celebration of divine worship, such as the decoration of the altar or church on occasion of some festival, and the like, although servile works, are not prohibited; and hence our Lord says: The priests in the temple break the sabbath, and are without blame.
Neither are we to suppose that this Commandment forbids attention to those things on a feast day, which, if neglected, will be lost; for this is expressly permitted by the sacred canons.
There are many other things which our Lord in the Gospel declares lawful on festivals and which may be seen by the pastor in St. Matthew and St. John.
The Baltimore Catechism (Papalist) states:
238. What is forbidden by the third commandment of God?While I'm sure there is a mental aspect to NFL, I think it's safe to say it is more labor of body than of mind. I'm not sure I accept the RC distinction, which seems to permit white collar work while forbidding blue collar work, but of the two being a linebacker seems plainly to be more about muscle.
By the third commandment of God all unnecessary servile work on Sunday is forbidden.
Six days shall you do work; in the seventh day is the sabbath, the rest holy to the Lord. (Exodus 31:15)
239. What is servile work?
Servile work is that which requires labor of body rather than of mind.
240. When is servile work allowed on Sunday?
Servile work is allowed on Sunday when the honor of God, our own need, or that of our neighbor requires it.
Of course, these days the CCC states:
2187 Sanctifying Sundays and holy days requires a common effort. Every Christian should avoid making unnecessary demands on others that would hinder them from observing the Lord's Day. Traditional activities (sport, restaurants, etc.), and social necessities (public services, etc.), require some people to work on Sundays, but everyone should still take care to set aside sufficient time for leisure. With temperance and charity the faithful will see to it that they avoid the excesses and violence sometimes associated with popular leisure activities. In spite of economic constraints, public authorities should ensure citizens a time intended for rest and divine worship. Employers have a similar obligation toward their employees.-TurretinFan