In a multi-radio wireless device, a first radio and a second radio share a plurality of antennas. A MAC coordination engine may coordinate the activities of the first and second radios to facilitate the allocation of antennas to the radios. In at least one embodiment, the second radio is given priority over the first radio in the allocation of antennas. When the first radio desires to communicate, a number of antennas that is available for use may be determined. It may then be determined whether the communication should be permitted to proceed given the number of available antennas.