Having fallen behind to Scott Parker's first-half opener, the hosts started the second period brightly and Kenwyne Jones equalised. Jones saw a shot tipped onto the post by Robert Green soon after as Stoke went in search of a winner, but the striker was then removed from the action. Jon Walters and Pennant were also substituted and the match finished level, with Kemp revealing afterwards that all three changes had been forced.
"We started very slowly and we are disappointed with the way we played in the first half," said Kemp. "I thought after half-time and getting the early goal, we started to play much better and had some opportunities that hit the woodwork, but the injuries didn't help us."
He added: "Every time we seemed to be getting a head of steam up, we seemed to pick up an injury to an important forward player.
"I think that affected us, so on reflection it could be two points lost, but maybe it was one gained. It is a groin with Kenwyne, a hamstring possibly with Jermaine and an ankle with Jon Walters.
"We don't know how serious they are - we will have to just wait and see."
West Ham were without manager Avram Grant, who was observing Yom Kippur. In his absence, Grant's senior coaching staff of Zeljko Petrovic, Paul Groves and Kevin Keen oversaw the Hammers as they secured their first point of the season.
Asked what his feelings were about the performance, Groves said: "It is tinged with a little bit of disappointment, because I felt after the first half we could have perhaps gone in 2-0 up and then they scored early on in the second half. But we also realise this is a difficult place to come to and get points against a strong, powerful side."
Another absentee for West Ham was Kieron Dyer, whose representatives have dismissed allegations that he had a heated exchange with Grant after being told that he would not be taking part in the match.
Groves denied there was any problem between Dyer and Grant, but when asked if the midfielder had turned down a place on the bench, he said: "That I wouldn't necessarily know. I know he is available, but he is being managed in terms of his injuries and availability, making sure that he is in good condition when it comes to playing football matches."
Source: PA
Source: PA