Liverpool could be without Sadio Mane for part of the Premier League run-in, with fears an injury picked up by the forward during the Merseyside derby may have long-term repercussions.
Mane scored the opening goal in Saturday's 3-1 win over Everton at Anfield, but he was forced off before the hour after his left leg was badly tangled in a challenge with Leighton Baines.
The Senegal attacker is the Reds' top scorer this season with 13 goals and an enforced absence would compound the recent loss of Adam Lallana to a thigh injury.
Mane is almost certain to miss Wednesday's Anfield meeting with Bournemouth, while the Reds' dip in form when the forward was away on Africa Cup of Nations duty earlier this season gives an ominous warning for the games ahead.
"Today we played a really good game," Klopp told a news conference. "Nearly everything was perfect.
"We win it, the performance was good [but] then we lose Sadio Mane. When I saw him in the dressing room, it didn't look like he'll be ready for Wednesday.
"We will see, hopefully it's not that serious, but of course it's not nothing and that makes our life not easier, I would say.
"Obviously he has pain and it didn't look like it's only a knock or a muscle or something, but we have to wait.
"When I came in I was looking for him immediately and I saw him on the bed. He'd already had treatment, and it didn't look like he felt really comfortable."