Following the timely service and filing of a notice of appeal, the NFLPA and NFL shall attempt to agree upon a briefing schedule. In the absence of such agreement, and subject to Subsection (d) below, the briefing schedule shall be set by the Appeals Panel; provided, however, that any party seeking to appeal (in whole or in part) from an award of the System Arbitrator shall be afforded no less than fifteen (15) and no more than twenty-five (25) days from the date of the issuance of such award, or the date of the issuance of the System Arbitrator’s written opinion, whichever is latest, to serve on the opposing party and file with the Appeals Panel its brief in support thereof; and provided further that the responding party or parties shall be afforded the same aggregate amount of time to serve and file its or their responding brief(s).