Celtic told to secure paperwork for De Rosario trial
De Rosario has been with Toronto in his homeland since 2009
Celtic must obtain official agreement with Toronto and Major League Soccer for midfielder Dwayne De Rosario to continue his trial period in Scotland.
The Canadian international's club and MLS say Celtic did not have permission for De Rosario to train with them and were surprised to learn he had done so.
MLS say Celtic chief executive Peter Lawwell told them that the player and his agent said they had permission.
The league will now work with Celtic "to secure the proper paperwork".
Celtic manager Neil Lennon was expecting the 32-year-old to train at the club's Lennoxtown base for a week.
The Canadian joined former Sweden international Freddie Ljungberg, another considering a move to the Scottish Premier League club, at training on Tuesday.
But a statement on Toronto's website said of their captain: "We were unaware of Dwayne's plan to train with Celtic. We will contact them to understand the situation."
He is a skilful, sharp and intelligent player
Celtic manager Neil Lennon
This was posted a day after the club insisted that De Rosario was not going on trial.
"Obviously, if there is interest in a short-term loan arrangement by either him or Celtic, they will need to approach us and the league formally and we will consider based on what is in TFC's best interest."
A statement by MLS on Wednesday said: "When we are told that by a club like Celtic we are inclined to not move towards a legal action and instead work with them to secure the proper paperwork."
Three-time Canadian player of the year De Rosario is still tied to Toronto for another two years but is in the middle of a contract dispute with the club.
Now with 55 caps for Canada, De Rosario played in Europe with German outfit Zwickau as a teenager before spending the rest of his career in North America.
He started out with Toronto Lynx and has since played for Richmond Kickers, San Jose Earthquakes and Houston Dynamo before joining Toronto FC in 2009.
Should the administrative matters be resolved, Celtic manager Neil Lennon will be able to further assess a player he likens to Shaun Maloney.
"He likes to play off the left and come inside," he said. "He is a skilful, sharp and intelligent player. Again, it's an opportunity for us to have a look."
Injury has denied Celtic the services of Maloney, while right-back Cha Du-Ri and midfielder Ki Sung-Yeung will be absent for much of January while playing for South Korea at the Asian Cup.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.