McCarthy was stretchered off the pitch after Rondon's accidental kick as he attempted a tackle broke his leg, leaving Rodon in tears seeing McCarthy in agony.
"His tibia and fibula have been broken from his really fearless efforts to stop West Brom with a possible scoring opportunity". "He's paid a heavy price for his bravery and commitment". I think it very much depends on the specialist or surgeon that deals with it.
"Now this is one serious injury which we know will keep him out until next season at some stage, that's a big blow".
The news will resonate strongly with Ireland and Everton fans, following Seamus Coleman's leg break against Wales past year.
It was Rondon who made the severity of the injury clear to the referee.
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The Glasgow-born central midfielder has been with Everton since 2013 when he joined for £13m from Wigan Athletic, linking up with former manager Roberto Martinez.
The midfielder was caught by Salomon Rondon during the second half at Goodison Park.
Just as Rondon pulled the trigger to shoot, McCarthy's planted his foot in front of the Venezuelan.
The injury was so severe, the television station broadcasting the match refused to show a replay of the incident.
West Brom's Salomon Rondon goes through the back of James McCarthy with a challenge which looks to have resulted ina broken leg for the Irishman. While the full-back is set for a return to competitive action after nine months out, his club and worldwide teammate will nearly certainly be out for as long, if not longer.
And his tackle proved even more valuable just after play restarted following his substitution when Oumar Niasse scored to earn a draw.