The incident happened in the Superbike/Superstock session, forcing a delay of almost two hours.
McGee, from Mullingar, had been third fastest in the Superstock class at the time on his Kawasaki after lapping at 129.248mph, while Ballymoney man Elliott had lapped at 124.612mph, which left him 19th in the Superstock session.
Earlier in the day, McGee had claimed provisional pole in the Supertwins and Ultra-Lightweight classes.
A statement from the organisers said: ‘As an update on riders from the earlier incident, Seamus Elliott and Derek McGee are being treated for suspected broken bones’.
The session was restarted over 25 minutes, with Dean Harrison topping the times on his Silicone Engineering Kawasaki with a lap of 132.451mph.