Borussia Dortmund general manager Hans-Joachim Watzke has claimed that the signing of Arturo Vidal will help Bayern Munich win the Bundesliga title again this season.
The reigning champions confirmed on Thursday that they had agreed a deal with Juventus for the Chilean midfielder.
Watzke believes that the addition of Vidal will see Bayern go on to retain their league crown this term and most likely the following year.
"He's got a warrior's mentality and that is combined with great footballing quality," he told dpa. "That's a huge transfer for Bayern and it's certainly going to do them good.
"The question as to who will win the title this season need not even be asked. Bayern are going to become the first club to be crowned champions of Germany four times in a row, and it's probably going to be five the following year."
Vidal spent four years playing for Bayer Leverkusen before joining Juventus in 2011.