The summer transfer window has now arrived and Celtic fans will be waiting eagerly to see what kind of moves the club pull off this time around. There is a need to improve the squad after what was an underwhelming campaign by their standards.

Yet, at the same time, there seems to be a recognition that some of their best players could be heading for the exit door.

That is not ideal if you are Celtic. But it is just the nature of life at Parkhead. Players join the club, do well, draw interest from top European sides and move on.

There is no reason to believe that the formula will change at Celtic this time around. On the contrary, there are more than one key players who could be headed for the exit door.

There has been all this talk about Daizen Maeda leaving after his heroic run of form top win Celtic the double. But he is not the only one in that position.

Celtic spent a record fee to sign Arne Engels from FC Augsburg. He has spent the next two years winning over the supporters.

But just when it had looked like he had succeeded in doing that, Engels could be his way out of Celtic Park. The Hoops, for their part, seem open to the idea as well.

According to Football Insider, Crystal Palace are plotting a move to sig Engels as Celtic are now prepared to let him leave this summer. 

Celtic received a pretty big offer for Engels in the winter window as well but did not entertain the idea of his exit in the middle of the campaign. But the report goes on to state that the club are now believed to be open to his departure for the right price.

What would that price be? We are not certain. But Celtic did turn down around £25 million to part ways with Engels last season.

He might not have been available for a transfer in the middle of a season but the situation has changed as it is not the summer and if he does end up leaving, Celtic will have a better chance of recruiting the talent who could replace him in midfield.

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One would imagine that Celtic would look for a fee north of £25 million to part ways with Engels this summer. It remains to be seen whether that kind of an offer does arrive on their table or not.

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