Being a goalkeeper must be strange. It's the only specialist position on the pitch and one mistake can write you into the history books for all the wrong reasons.Because of this, 'keepers tend to stick together in the goalkeeper's union, and are often quick to heap prise on one another when it's deserved and jump to each other's defence when the criticism gets out of control.It's a heartening thing to see, and the camaraderie shown on the pitch between two custodians can often bring together fans away from the field of play.Recently, Porto stopper Iker Casillas and Juventus legend Gianluigi Buffon have been sharing a very public footballing love-fest, hailing each other as the other's inspiration.During our lifetime we've been lucky to see these two titans of the game compete against each other at the highest level for both club and country, so when they take some time out to talk about one another we're always more than happy to listen.But that apparently doesn't extend to other goalkeepers, as Iker himself found out last week when posting a seemingly innocuous tweet about another talented stopper.Earlier in the week, football fans may have seen a video doing the rounds showing a series of top class saves from Atletico Madrid keeper Jan Oblak, who managed to pull off three consecutive blocks to keep Levante at bay.The Czech foiled a one-on-one before getting back to his feet to foil the rebound before making one more block and seeing a final shot drift by his far post and out of danger.Casillas, like most of us, was impressed by his counterpart's agility and awareness, and posted his own tweet to highlight just what a feat of athleticism he thought it was.He didn't say much in his tweet, all he did was post a number of ghost face emojis along with a link to the video. Pretty innocent, eh?

But that didn't seem to go down too well with his fans back at the Bernabeu, who reacted angrily to him highlighting the work of one of their rivals, and promptly let him have it in the replies, as reported by Spanish publication AS.

Given that Atletico are out of the title race in La Liga this season, it's surprising that they were so wound up by the tweet. 

Check out the reaction below.

Despite this, though, it's unlikely that it'll stop the veteran from praising other goalkeepers in future.