Meyler, 20, came off against Man Utd on Sunday with suspected cruciate knee ligament damage.
The impressive midfielder was unfortunate to end his great opening season as a Sunderland player on a stretcher in the last home game of the campaign.
Meyler has been for a scan and everyone at the club is hoping for some positive news.
Steve Bruce added: ‘The first indications are that it is not good at all.
“It looks a nasty one. We fear that he has done his cruciate knee ligament, so that is a huge blow.
“It was only the kid`s 12th appearance, but he has had such an impact for us.
“He will go for scans and X-rays and what have you over the next 24-48 hours.’
Hopefuly Meyler can recover from this injury and get back into the Irish set up as he was recently called up for summer camp with Trapattoni’s squad.