Born in Montevideo, Uruguay, Polenta started his career on hometown's club Danubio, in youth categories. His abilities impressed the Italian club Genoa, and he was moved to the club in July 2008.
Genoa C.F.C.
He spent the whole 2009-10 season with the Primavera team. In the 2010-11 season he was included on the first team squad, with the 35 jersey.
On 30 April 2011, he made his first team debut, against Napoli, after came off the bench to replace Giandomenico Mesto.[4]
A.S. Bari
On 29 August 2011, he signed a season-long loan deal with the Serie B club Bari in order to gain first team football experience.[5] After a successful stay that loan deal was extended by one year on 21 August 2012. He stayed with Bari until 2014.
[6]
He subsequently became the Captain of Nacional. In July 2017 he won the Torneo Intermedio Final.[8]
In July 2018, with Polenta's contract expiring at Nacional at the end of June 2018, Spanish Newspaper El País, reported that Polenta had received contract offers from Mexican side Club Atlas, Saudi Arabian side Al-Ittihad and English side Leeds United, with the player taking time to consider the proposals.[9]
LA Galaxy
On 7 February 2019, Polenta joined MLS club LA Galaxy. On April 19 he scored his first goal for the club, a late winner against Houston Dynamo.[10]