The Arsenal star believes he shares qualities with the world's best players.
The German goalkeeper was available at a cut price fee.
Will these new recruits at Aston Villa, Wolverhampton Wanderers, Derby County, Sheffield Wednesday and Fulham make the debuts this weekend?
Leeds United have added a number of new attacking options to their side.
Leeds United new boy Eunan O'Kane is in contention to feature this weekend.
Griffiths was absent as Brendan Rodgers' side stepped up their preparations for the meeting with Rangers on Saturday.
Two of the promoted clubs face each other on Saturday in this pivotal early season clash. So who will be the men to propel their teams to victory
Crystal Palace will be hoping to finish in the top half of the Premier League after spending vast sums of money throughout the transfer window.
Spurs visit the Potters on Saturday afternoon chasing a second Premier League win of the season.
Rangers boss Mark Warburton brought Barton to Ibrox this summer.
West Ham United are reportedly just £4m away from securing AC Milan striker Carlos Bacca.
The Barcelona and Argentina football star Lionel Messi goes on trial on Tuesday on charges of defrauding Spain of €4.1m (£3m) in unpaid taxes.
Robbie Keane, the Republic of Ireland captain, has been forced out of the pre‑Euro 2016 friendly against Belarus on Tuesday night with a calf injury and his manager, Martin O’Neill, has admitted that the veteran striker is now a serious concern for the tournament.