Sunderland needed to bolster their ranks in the goalkeeping department following the release of both Kieran Westwood and Oscar Ustari earlier this month, but the acquisition of a player of Pantilimon's quality suggests that Gus Poyet is looking for more than merely cover for Mannone.
The Italian enjoyed a fantastic first season on Wearside and his many important contributions - most notably the penalty shoot-out heroics in the League Cup semi final - lead to him being named Sunderland's Player of the Year, voted for by the fans.
But it now appears that the 26-year-old will see his position come under serious threat at the Stadium of Light as Poyet brings in stiff competition for a place between the sticks.
Standing at a gigantic 6"8, Pantilimon is a towering presence and has showed glimpses of being a very capable goalkeeper during his time at Manchester City.
Arriving at the Etihad in 2011, the 28-year-old was made to be extremely patient and made only seven Premier League appearances for the club before running down his contract.
Now as he joins Sunderland, it's unlikely that the Romanian international will be content in warming yet another bench in the Premier League. Meaning Pantilimon is more likely going to be expectant of a place amongst the starting eleven next season.
Often it can be possible for two goalkeepers of the same standard to exist at one club providing there are plenty of opportunities for both to play, but at Sunderland this simply will not be the case. With no European football, first team opportunities for one of either Mannone and Pantilimon are going to be few and far between.
Whilst the quality of the signing is not in question, the motivation is. Does the signing of Pantilimon suggest Poyet lacks faith in his current number one? or is the Uruguayan looking to bring serious strength in depth to Sunderland?
Black Cats fans will undoubtedly be excited by the prospect of having two very good goalkeepers on their books, but they will not want to see their favourite replaced.
After many years warming the bench himself at Arsenal, Mannone has earned his position as Sunderland's number one. The Italian was recently listed in a study as the best value for money goalkeeper in the Premier League, and he will be reluctant to give up his place in the first team without a fight.