Southgate said: “With a bit more luck, Dong-Gook could have had a couple of goals under his belt already.
“He’s got a good attitude. He wants to go well and he wants to score goals.
“That’s why he was keen to take one of the penalties at West Brom.
“We still have some work to do on his fitness, so we can’t just throw him in yet.
“It’s not easy adapting to a different culture and we’ll give him the time he needs. But he has done very well for us so far and that’s a good sign.”