Back on December 17th, the Rays made the bold choice to deal away the prize of the James Shields trade and 2013 Rookie of the Year, Wil Myers, to the San Diego Padres in a massive 11 player deal between three teams. The Rays received several prospects, while also sending away couple of their own, along with Ryan Hanigan. Rene Rivera had been the Padres starting catcher in 2014 and he enjoyed a breakout year for the Friars, he would be just a sidenote heading to Tampa Bay in the deal.
With Ryan Hanigan heading to San Diego and Jose Molina being released just a few weeks before, Rivera was going to be the Rays starting catcher. He had only one full year in the majors, which had been the 2014 season in which he slashed .252/.319/.432 with 11 HR and 114 wRC+. That kind of offense would Rays fans very excited, especially considering the offense that was provided by Jose Molina.
Something else Rivera was surely to be an improvement at was defense, as Molina struggled behind in the plate in pretty much every category but framing. Rene Rivera put up 15 defensive WAR last year, while Molina put up only two defensive WAR. Rene Rivera was actually close to, or even better than Molina at framing last year as well, so it's safe to say the Rays were expecting a vast improvement behind the plate, after all, Molina was historically awful last year.
So far this season, Rivera has slashed .163/.201/.276 with 4 HR in 203 PA in 66 games, giving him 33 wRC+ which is somehow lower than Jose Molina's offensive production through 66 games last year in which he put up 35 wRC+. Perhaps the only saving grace for Rivera is he's hitting the ball out of the ballpark, or at least for extra bases making him much more effective than Molina last year. Also, Rivera sports a .200 BABIP, while it was .300 last year, suggesting that it may just be the result of some bad luck and he's due for some positive regression.
One thing Rivera has brought with him, that the Rays desperately needed, is the ability to throw runners out. He started the year by only nabbing two of 14 base stealers, but since that time he has caught over 50% of players attempting steal, as has caught 17 players so far this year out of 42 (40%). Rivera's 17 is already three more than Jose Molina had during all of last season.
Although Rivera has committed a league high seven errors this year, he's been one of the better defensive catcher in the AL this year. According to statcorner, Rivera ranks 5th in the AL in RAA (Runs Above Average) with 5.2. However, Rene Rivera is tied for second in the majors in wild pitches/past balls allowed with 29. So by the the traditional standards, Rivera has been awful behind the dish, but has a cannon for an arm displayed by his CS%, by some of the more advanced metrics put him at least in the middle of the pack as far as defense goes.
As for his offense, this should improve hopefully as the season goes on. Several projection systems have him slated to raise each of his slash averages at least .50 points so that'd be a big boost to his black hole in the lineup.