West Ham manager Slaven Bilic fears serious injuries to Dimitri Payet and Enner Valencia could derail his side's impressive start to the Premier League season.
Hammers manager Bilic was left reeling after Payet and Valenica both suffered ankle problems in Saturday's 1-1 draw against Everton at Upton Park.
French midfielder Payet, who has been instrumental since joining from Marseille in the close-season, limped off soon after a first-half tackle from James McCarthy.
Ecuador striker Valencia was stretchered off with a serious looking injury following an innocuous challenge from Seamus Coleman.
With West Ham making a surprise push for a coveted Champions League spot, those losses could potentially prove a damaging blow as Bilic awaits news of scan results.
"We have to wait about Payet and Valencia. It doesn't look good but I'm not a doctor. I have been in football
long enough not to listen to first opinions," Bilic said.
"They are almost not always accurate. It's better to have a scan and then see. The first one was a bad challenge and the second was a typical English tackle -- ball and everything.
"It does not look good but I'm hopeful and staying optimistic."
West Ham led through Manuel Lanzini's curling strike before Romelu Lukaku equalised just before half-time.
It was the Belgian's seventh goal in as many games against West Ham as he joined former great Dixie Dean as the only Evertonian to score against the same opponent in that number of matches.
West Ham sit fifth in the table heading into the international break and Bilic is content with how things have gone so far.
"We have to be happy with our start to the season. We need to use this international break to come back ever hungrier. I have told the players to be proud but to come back hungry," Bilic said.
"It's one third into the season so I have to be happy with the way we played. It's a good position to be in. The expectations for ourselves is to stay as high as possible.
"We are going well but we hope to improve and stay high. We need to stay away from injuries. You hope that doesn't happen again like in this game."
Meanwhile, Roberto Martinez is optimistic his Everton side can challenge for a top-four finish.
The Toffees are seven points adrift, but Martinez says performances like Saturday's will boost their chances.
Despite Lukaku snagging the headlines, it was John Stones who stole the show with a commanding man-of-the-match display that underlined why Chelsea were so keen to sign him in the close-season.
"It was a really interesting challenge for John as it wasn't just about defending. It was about leading that back four," he said.
"We had five players injured. John has to lead the defence -- that's where I was most impressed.
"I thought he was immense. It's not an easy job having to defend against a striker like Andy Carroll."