Ajax boss John Heitinga saw his side undone early on when Kieran Tierney picked out Reo Hatate with a precision pass in behind their advanced backline, allowing the midfielder to square for Yang Hyun-jun to finish at the back post.

In the early stages, Celtic’s sharp movement caused problems for Ajax. Tierney’s ball in behind exposed their high line, with Hatate timing his run perfectly to set up Yang for a tidy finish. It showed the danger of pushing up too far against a side with that kind of precision.

Heitinga pointed to the problems created by Celtic’s controlled passing. Ajax’s shape was tested as players rotated positions, leading to gaps and confusion. When Ajax lost the ball or pushed forward, they were left facing one-on-one situations across the pitch.

The first half asked serious questions of Ajax’s ability to defend under pressure. Celtic’s use of width and fresh legs only increased the difficulty. As Ajax tried to push up again, they often left too much space behind, relying on individual defending instead of a solid team shape.

Heitinga said: (ESPN), “The line of possession to their striker [Adam Idah] was often open. When we pushed forward, we were often one-on-one defensively. Then you have to win all your personal battles.

“They had a lot of positional changes, and we struggled with that quite a bit in the first half.

“When we lost possession, we weren’t always positioned well. That’s the most important lesson from the first half.”

Heitinga’s comments focused on how Celtic found space through smart movement and quick forward play. It was a clear sign that playing a high line needs sharp organisation and focus, especially against a team that can pass through gaps with ease.

It wasn’t just a tactical issue. Celtic won too many individual battles, showing Ajax’s problems when having to defend on the back foot. When they gave the ball away, they didn’t have enough players in the right positions to deal with the danger.

Celtic took full advantage in the first half, but the game flipped after the break. With Tierney off at half time, Celtic lost their shape and discipline. Ajax punished them with four second-half goals, turning the match on its head and running out 5-1 winners.

The final scoreline reflected a dramatic collapse. Without Tierney’s composure and control on the left, Celtic’s back line became stretched and disorganised, allowing Ajax to cut through far too easily.