Newcastle's Howe says Isak relationship was 'difficult' before Liverpool move

Isak moved to Liverpool for £125 million ($169 million) on transfer deadline day after Newcastle finally gave in to his demand to join the Premier League champions.

The 25-year-old missed Newcastle's pre-season tour to Singapore and South Korea due to what Newcastle said at the time was a minor injury.

Isak trained at his former club Real Sociedad while Howe's team were in Asia and then worked on his own as Newcastle prepared for the new season.

Howe was instrumental in Isak's rise to prominence after signing him from Sociedad, with the Swede's goals helping to end the club's 56-year trophy drought and secure Champions League qualification last season.

But Howe said their relationship soured once Isak refused to take part in the pre-season, which effectively ruled him out of Newcastle's first three Premier League games.

"Alex and I always enjoyed a great relationship. I loved working with him, and I hope he loved working with us," Howe told reporters on Friday.

"It was mutually beneficial. We helped him become the player that he is today, and he helped us as a team achieve some unbelievable milestones. He was part of a very successful team.

"But to give you a bit more on that, the moment he went on strike, our relationship did change. I think that was probably a turning point in our relationship. Communication became difficult from that point onwards. I won't go into any more detail than that."

Isak's departure prompted Howe to sign Stuttgart's Nick Woltemade and Brentford's Yoane Wissa as replacements.

Germany striker Woltemade could make his debut against bottom-of-the-table Wolves at St James' Park on Saturday, with Newcastle still seeking their first win of the season.

But DR Congo forward Wissa will not be involved after returning from international duty with a knee injury that could also rule him out of Thursday's Champions League opener against Barcelona.

"I saw him for the first time yesterday; he's feeling the effects of the injury he sustained just before he came off, so we're going to have to see how he is," Howe said of Wissa.