It sure can. As soon as a trade proposal is agreed upon by both sides, a 24-hour owner approval process begins. During this time, each owner may choose to approve or reject the trade proposal. After the approval period expires, the votes are tallied and the trade is either completed or vetoed. The number of votes required to veto a trade could be different in each league. The league founder has the ability to specify how many votes are needed in Theme and Dynasty Leagues. The trade proposal screen (in the GM's Office), will always display the number of votes needed in your league.
Remember, your veto vote isn't a secret! The owners will see who approved and who rejected a trade. Who knows how this could affect your future wheeling and dealings?
Please Note: All roster moves are blocked during the 2 hours before game time. If the 24-hours approval period expires during this time period, the trade will not be completed until the games are played.