Christo BuchnerDurban – Sharks coach John Plumtree said on Wednesday that Guy Cronjé's unavailability due to suspension is a huge blow to his side. But he hopes the young flyhalf will learn his lesson early on in his career.The defending champions will have to take on the Blue Bulls without Cronjé on Friday night in their Currie Cup match at the Absa Stadium.The 19-year-old was found guilty by a disciplinary committee chaired by Dekker Govender of making a dangerous spear tackle on Boland lock Frikkie Spies in last Friday's match"You have to play according to the rules. To me, the tackle looked rather innocent, but the guys who had to make the ruling saw it a different way and we have to accept that," said Plumtree. Normal 0 false false false MicrosoftInternetExplorer4 After being lifted into the air, Spies fell to the ground head-first. "If you pick up a player like that in a tackle, you have to put him down carefully," explained Plumtree.Cronjé has been suspended for a week and will be replaced by Monty Dumond at flyhalf against the Bulls. It is the only change to the starting team that beat Boland 46-10. Dumond's place on the bench will be filled by the former Falcons player, Len Olivier."Guy played well against Boland and we would've liked him to keep up that momentum. We will now have to adjust, but Monty is an experienced player who knows what is expected of him."Plumtree had much praise for the young Bulls, especially flyhalf Francois Brümmer, who has played well since making his Currie Cup debut two weeks ago.