But Black is confident speculation over the future of the player and his team-mates ahead of the January transfer window will not affect performances on the park.
Polish club Lech Poznan is rumoured to be preparing a £170,000 bid to land the 21-year-old Estonian international.
Black said: "An Eastern European club has declared an interest in the player. There has been an initial enquiry from another club.
"We have had speculation about Jamie Murphy for the last two or three weeks and now there is speculation about Henrik.
"But we have got a group of focused footballers at the club and I am sure there will not be any issues arising out of the stories.
"It is no secret that agents will next month be trying to get the best deals they can for players who are out of contract at the end of the season.
"They will be working to get the best deal they can do for their clients. They are well within their rights to do that and clubs can also express interest in players.
"We just have to accept that as a club. I know all of the players are looking forward to finishing off the season as well as possible."
Stuart McCall's side moved into second spot in the Clydesdale Bank Premier League at the weekend with a stunning win over high-flying Hibs at Easter Road.
Having fallen 2-0 behind, the Steelmen staged a gritty fightback and second-half goals from Murphy, who bagged two, and Robert McHugh sealed a memorable triumph.
The victory meant Well, who play St Mirren in Paisley tomorrow night, leapfrogged Inverness into second spot in the table.
Having been knocked out of the Scottish Cup, Black is hopeful Motherwell's players can push for a European place this season.
He said: "It was disappointing to get knocked out of the cup in the replay to Aberdeen. But we really enjoyed being involved in European football this season and getting back there will now be our focus.
"We only have league games to play. The result at the weekend and moving second in the league will certainly give us confidence.
"Our games with St Mirren have been close and I am sure tomorrow night's game will be the same. But playing on a Friday night gives us a great chance to put pressure on the teams around us.
"I am sure there will be more changes in position near the top of the league before the season is out. But we certainly have an opportunity to open up a little gap with our game being on a Friday night."