Everton boss Ronald Koeman felt Ross Barkley's performance against West Ham was hugely improved, but stressed he needs to "run more" if he is to become a top player.
Barkley's late strike sealed a 2-0 victory at Goodison Park on Sunday, ending a four-match winless run in the top-flight as the hosts consolidated their grip on sixth position in the table.
The 22-year-old has had a difficult 2016-17 campaign, losing his place in the England squad since being an unused member of their Euro 2016 group and being left on the bench for his club's draw with Manchester City earlier this month.
Prior to his strike against West Ham, Barkley had been repeatedly warned over his performances by Koeman, with the Dutchman still proving hard to please after the match and urging his player to up his work-rate despite praising his improvement in the match.
"He had more impact in the last part of our attacking," Koeman told Sky Sports. "Not only scoring the second goal, he was also really dangerous outside the box.
"He had some good passing and shots on target. That's what the team needs from these kind of players that are offensively strong. That's the player that we want.
"He can be very good, but it's all about knowing what you need to do. Sometimes I still have to shout too much for him to come back to the midfield and he takes a rest by the side of Romelu - that's not what I like.
"You can take your rest but first come back to your position. He needs to run even more because he's physically so strong.
"He can do much more but today he showed a good way."
Koeman revealed he had stern words to his players at the half-time break that had proved crucial to their victory, with Romelu Lukaku's 50th-minute headed opener freeing his side up.
He added: "I think the key was what we didn't do well in the first half we did good in the second half.
"We were struggling a little bit maybe after the last few results and had a few doubts on the pitch.
"We looked a little bit nervous but the second half was different. From the start of the second half it was higher tempo, better pressing and we deserved the win. The first goal gave us that confidence that you need to play good football. That was the important moment.
"Yeah [it was heated at half-time]. I asked them, 'Why we are doubting [ourselves], we play at home, we of course know West Ham are on a good run and a strong team, but believe and show more confidence - go for it'.
"That was really the difference between the first and the second half."