Cleveland Browns strengthen OL with signings

March 9 (UPI) -- The Cleveland Browns made Kevin Zeitler the highest-paid guard in NFL history when the two sides agreed on a five-year, $60 million deal, according to multiple reports on Thursday.

Zeitler will receive $31.5 million in guaranteed money. His $12 million average per year exceeds the previous high for a guard landed by Oakland's Kelechi Osemele ($11.7 million average on a five-year, $58.5 million deal).

Zeitler, who turned 27 on Wednesday, was the starting right guard for the Cincinnati Bengals over the past five seasons. He played every offensive snap last season.

The big signing wasn't the lone development for Cleveland's offensive line.

The Browns signed left guard Joel Bitonio to a five-year, $51 million extension, and agreed to terms with former Green Bay Packers center J.C. Tretter as a free agent.

Bitonio, 25, received $23 million in guaranteed money. He played in just five games in 2016 before undergoing season-ending foot surgery in October, but is expected to be ready by the start of the regular season.

Tretter, 26, started 10 games for Green Bay last season. He suffered a knee injury during the season and underwent surgery in January. He is slated to be recovered by the start of the season.

Browns head coach Hue Jackson has a history with Zeitler. Jackson was Cincinnati's offensive coordinator in 2014-15.

Zeitler started 71 of 72 regular-season games with the Bengals.