Newcastle United boss Chris Hughton claimed the shine had been taken off Saturday's 1-0 victory over Everton following an injury to goalkeeper Steve Harper.
Harper had to be replaced by Tim Krul in the 35th minute of the Goodison Park encounter following a collision with home striker Jermaine Beckford.
The Magpies went on to win the game courtesy of a first goal for the club from new signing Hatem Ben Arfa, but afterwards Hughton's thoughts were with the long-serving goalkeeper who he fears could be sidelined for a significant period of time.
"I thought it was a challenge that didn't need to have been made," he explained."Steve Harper was always getting there first.
"It looks like a shoulder ligament injury, which will keep him out for a period of time.
"How long, it would be a little bit unfair of me to say because we won't know until the next few days."
Meanwhile, Hughton was pleased with the response to last weekend's 2-0 home defeat to Blackpool.
He added:"The most pleasing thing for me was the team performance. It was a real disappointment last week because it's a home game and we know how valuable points are in this division. We saw it very much as three points lost last week.
"Is Goodison an ideal place to come on the back of a defeat? The answer generally is no because of the quality they've got here.
"But I thought it was an excellent performance from the first to the 94th minute."Subscribe to Football FanCast News Headlines by Email