By Jamie Spencer Brentford have completed the signing of Liverpool defender Sepp van den Berg on a permanent transfer for up to £25m – including add-ons. Van den Berg, who has signed a five-year contract with the Bees until 2029, is the second player to move from Liverpool to Brentford at vast expense this summer after Fabio Carvalho. The Portuguese attacker sealed a £27.5m switch to west London earlier this month. Brentford are unsurprisingly pleased with their capture of Van den Berg. “I think this is a great signing for the club and the team,” manager Thomas Frank said. “Sepp is a centre-ba…