Portuguese side Sporting Lisbon are to complain to FIFA after three of their development squad players trained with Chelsea, the club said yesterday.

Teenagers Adrien Silva, Fabio Ferreira and Ricardo Fernandes worked out at Chelsea without authorisation from Sporting, the club said in a statement.

A response from Chelsea to Sporting's complaints showed the English Premier League leaders wanted to recruit the players without following FIFA rules, the Lisbon club said.

"Sporting will appeal to FIFA, with the knowledge of (European soccer body) UEFA, for disciplinary action to be taken against Chelsea FC," the statement said.

"Sporting believes that FIFA will know how to protect those who, following its own recommendations, invest in and promote football development at high cost, as in this case."

A Chelsea club spokesman was not immediately available for comment.

Meanwhile, Arsenal manager Arsene Wenger has insisted he will still not be forced into the transfer market despite Arsenal falling seven points behind leaders Chelsea amid an injury crisis.

The Arsenal boss admitted his depleted side were too inexperienced in last night's costly 1-1 home draw against Manchester City. The result left them trailing even further in Chelsea's wake, with Wenger conceding they now face their biggest title hurdle yet to make up the deficit.

However, he vowed not to give in, stressing that conceding defeat with 16 games still left to play would be "criminal".

"We did not have the right balance between experienced and inexperienced players, especially at the back," admitted Wenger.

"But I'm not a big fan of going out to buy a new player every time you have a disappointment. If you don't have a good season, you would finish with 25 players!"