Ronny Deila last night watched central defender Virgil van Dijk rattle Celtic into an eight-point lead over Aberdeen - and then revealed that he is still on the hunt for his possible replacement.

Van Dijk netted a sumptuous free-kick to help Celtic to a 2-1 win at Dens Park, a result that takes Celtic a step closer to the league title.

But the Dutch defender has been the subject of speculation linking him with a move south of the border at the end of the season, while fellow central defender Jason Denayer is also keen to return to Manchester City at the end of the campaign.

And it is believed that Celtic have teed up Belgian under-21 internationalist Brandon Mechele as a possibility to take over what could be a vacant central defensive position.

The Club Brugge defender is believed to have been the subject of an inquiry from Celtic and while Deila did not want to talk about players at other clubs he did acknowledge that he is in the hunt for another stopper.

"I don't want to comment on players who are at other clubs - I learned a lesson on that," he said. "But it is fair to say that we are looking for defenders.

"I am not going to talk about any names at this stage but we know what the situation is. We have been planning for a long time.

"It is important to us that we have players who can come in and be ready to play because we have such important games in July. So we are always looking and always trying to get better. We know what we want."

Hearts' Danny Wilson has also been on the radar of Deila. The Tynecastle side have confirmed that Wilson will activate a release clause in his contract.

"We have a list of targets, "said Deila. "We are looking closely at what we need to do. "

The Celtic manager, meanwhile, has admitted that he needed the game against Dundee as much as any of his players did.

"It was the toughest day of my career on Sunday, really tough," he said. "It was really tough.

"Sunday and Monday were very tough. But now they are gone.

"I just want to keep winning games and get that league title to Celtic Park. Then we have done a good season."

Despite still being sore about the handball incident, Deila sees no purpose in retrospective action keeping Inverness defender Josh Meekings out of the William Hill Scottish Cup final on May 30th.

The finger of blame has been pointed in Celtic's direction because of the statement they release revealing that they had written to the SFA to request an explanation for the decision not to award a spot-kick.

The following day it emerged that the SFA compliance officer had issued a notice of complaint to Meekings.

"It doesn't help us," said Deila. "I don't think he does it on purpose. It is going very quick and it is a reflex action but it is a clear handball.

"To ban him afterwards, I don't think that is right. Always the best players should play in the finals."