The Portuguese manager was in attendance for the Old Firm derby yesterday.
Sunderland goalkeeper proved a liability as David Moyes' side exited the FA Cup.
The Black Cats signed Mika in mid-September.
Sunderland have signed goalkeeper Mika from Boavista following an injury to Vito Mannone.
The goalkeeper joined the Black Cats earlier this week.
Sunderland failed to sign the Boavista goalkeeper on deadline day but have now been given the go ahead.
Sunderland are reportedly set to sign goalkeeper Mika.
Sunderland make request to FIFA in an attempt to secure the services of Boavista goalkeeper Mika.
The Portuguese 'keeper's move is the subject of an appeal to Uefa.
Leicester City are looking to build in the summer transfer window.