Richard Sherman might think he’s a shutdown cornerback in the NFL. He might even go so far as to say he is the best cornerback at shutting down opposing receivers in the league. But no matter how much he talks, he still can’t convince everyone.

The newest person to question Sherman’s ability and worth is Arizona Cardinals’ cornerback Patrick Peterson. On Thursday, Peterson responded to a tweet Sherman made on May 13 by saying that the Seahawks’ cornerback wouldn’t survive against the Cardinals’ defense. Peterson added fuel to the fire by saying he does more than Sherman.

Sherman’s tweet had been instigated when Peterson said he believed he deserved more than the $57.4 million contract extension Sherman received. Sherman is not new to Twitter, nor is he exceptional at keeping his mouth shut when he feels wronged. The star cornerback for the Seahawks tweeted, “Want what I got? Get the stats I got! Least targeted #opinionvsfact”

Here we have the latest installment of the Sherman Chronicles, the sob story of a man who simply can’t let his performance do the talking. He has the most interceptions over the last three seasons with a total of 20. Peterson has only 12, and here he is claiming to be a more valuable player than Sherman. If Sherman had allowed the statistics on paper to do the talking, Peterson would look stupid as most people would compare the two players at face value.

But whenever Sherman draws more attention to himself than to his performance on the field, observers must delve deeper. According to ESPN, Peterson has indeed done more than Sherman. He has played 44 snaps on offense and has returned kicks and punts. He has racked up 151 tackles over the last three years, while Sherman has stayed behind at 138.

While talking Thursday on a Phoenix radio show, Peterson recognized that Sherman had the statistics to back himself up. Yet Peterson said Sherman was not a shutdown cornerback in terms of man-to-man coverage.

It is true that Peterson plays more roles than Sherman. It’s even plausible that Sherman would not succeed on a different team, but that is exactly why he signed an extension with the Seahawks. He works well in their system, and Seattle wants to keep him. It is irrelevant how well he would play on a different team.

What other players say off the field should be irrelevant to Sherman as well. Unfortunately, though, his trash talk potentially taints a promising career. In the future, he would be wise to keep his opinion of himself to himself and to let the facts on the field dictate how people view him.