Stoke City boss Paul Lambert has said that his team will have to be wary of Marko Arnautovic when the Potters welcome West Ham United in the Premier League on Monday night.
Arnautovic netted 26 goals during his four seasons at Stoke before joining West Ham last summer.
The Austrian initially struggled to settle at the London Stadium, but has been in impressive form in recent weeks.
Lambert has admitted that Stoke will have to "stop" the 28-year-old if they are to pick up a positive result at the bet365 Stadium.
"I don't know the guy personally but he had some good years here and scored a lot of goals, and assists as well. I saw him last week and he was very good," Lambert told reporters.
"When you lose guys like that you lose a big chunk of goals in your team. It's a big loss but for whatever reason he left the club. He's West Ham's player and we have to stop him."
Stoke are currently 19th in the Premier League table - four points off 17th-placed Crystal Palace.