West Brom boss Alan Pardew blamed fatigue for their defeat to Southampton.
Saints came from behind to claim a 3-2 victory at The Hawthorns.
He said: “I thought our options were limited in terms of resting certain players today.
“I think we covered more distance at Manchester City on Wednesday night than we have in any other game this season.
“And I think that showed today. Southampton looked a yard quicker than us.
“The 20 minutes before half-time knocked us.
“We couldn't get a grip of the game and they were dominating.
“It was unfortunate for us that they scored twice in that period with two quick goals.
“We huffed and puffed in the second period and pushed the game, but we didn't really threaten enough.
“When you're up against a team that are a little bit fresher they can slow the clock down and manage the game which was frustrating for us."