Celtic seem to be making their moves in the summer transfer window now, after a slow start. They are already believed to agreed personal terms with Camilo Duran and could be set to sign the Colombian striker soon.

On the other end of the pitch, Celtic might need some help as well. Kasper Schmeichel has retired after suffering a serious injury last season.

Viljami Sinisalo deserves a ton of credit for the job that he did after stepping in last season. But is he the long-term number one for Celtic?

Even if the club view him as capable of that role, at the very least, they will need to bring in a quality option to compete with Sinisalo for that starting spot. And it looks like they are trying to do exactly that.

According to a report from German outlet BILD, Celtic and Feyenoord Rotterdam are both keen to sign Tjark Ernst as their new number one. They are prepared to immediately trigger his €5 million release clause.

Ernst currently plays in the German second division for Hertha Berlin. And after a standout season, he might be looking for a move away.

Of course, many Celtic fans might raise an eyebrow at the prospect of signing a second division goalkeeper as the new number one.

Ernst's underlying numbers suggest though that he is more than capable of taking up that role, if he can make the adjustment to Scottish football and the pressure that comes with life at Celtic.

The first thing that you look at a goalkeeper is his ability to keep the ball out of his net. And Ernst did an exceptional job of that last season.

Ernst faced an xGOT of 52.52 and conceded just 44 goals. In total, he made 99 saves at a 69.2% save percentage.

Another thing that is vital for a Celtic goalkeeper is your ability with the ball at your feet. Oftentimes, the Hoops focus on building out from the back with the goalie viewed as the first line of that.

READ MORE: Celtic reach agreement as transfer closes in

Ernst is above average in that department without being exceptional. But it is worth pointing out that he did not make a single error leading to a goal, so he is reliable, which is just as important.

Also, he is 23 years of age. So, there is time to tighten up some things and improve his overall game. As a shot-stopper, there cannot be many complaints.

Ultimately, it will be reassuring to Celtic fans that the club are ready to make an investment in strengthening between the posts and trying to someone with a long-term vision rather than bringing in another veteran for a year or two, and repeating that cycle.

Roundtablesports is Free to join! You can post your own thoughts, comment on articles, and start conversations with our Roundtable Writers. Scroll up to the top of the page and click 'Join'.

Download the FREE Roundtable APP, and get even easier access to your favourite teams and news!