Germany international, a previous Arsenal target, is waiting to see what happens before making a final decision over his future with just one year remaining on his current deal
The 26-year-old Germany defender is tied to Werder until June 2012, but last week the club's general manager Klaus Allofs said budgetary constraints would make extensions hard to push through.
And Mertesacker is waiting to see how developments in Germany unfold before making a final decision over his future following his recent troubles with injury.
"I have another year on my contract with Werder, so we'll have to see what happens," he told Fifa.com.
"Taking a long-term view, the English Premier League is the more appealing option. The Bundesliga has steadily improved in recent years, but England and Spain are still ahead, because that's where you find any number of top clubs.
"I'm not ruling anything out, but it is extremely attractive. Moving abroad brings you on both as a player and a person."
Mertesacker has been with Werder Bremen since 2006 when he joined from Hannover.