The second-year player out of Michigan State came up big in Miami's 16-13 win over the New York Jets on Monday night.
He caught four passes for 58 yards - both career highs - and made some crucial blocks in the running game and in passing situations, giving the team confidence heading into Sunday's game against the Baltimore Ravens.
''It's his second year, and he's starting to really make a positive impact and a positive contribution, not that he hasn't before but it's probably been more noticeable,'' Dolphins coach Joe Philbin said. ''We've been asking him to do in his second year more things than he did maybe in his first year. He's shown up in the passing game more. . I like the trend that he is on.''
At 6-foot-4 and 265 pounds, Sims is an inch taller and 10 pounds heavier than Clay, who has been out with a hamstring injury.
He lined up in the backfield in the first quarter and sped across the formation to deal with blitzing linebacker Calvin Pace just before he got to quarterback Ryan Tannehill. That allowed Tannehill to complete a second-down pass to wide receiver Mike Wallace for 25 yards and a first down.
Sims nearly matched his total number of catches all last season against the Jets, and his 20-yard reception with one minute left in the first half helped set up Caleb Sturgis' 43-yard field goal as time expired.
Being able to produce in both aspects of the tight end position sits well with Sims. And with Clay back at practice Wednesday in a limited fashion, it makes the offense stronger.
''It's good just to be versatile, to be able to block and make catches,'' said Sims, who caught six passes for 32 yards and a touchdown as a rookie. ''I have to protect the quarterback first and for him to know that I can protect his blindside, and just him trusting me to be there to get the job done is good.''
Sims believes he has gotten faster and understands the Xs and Os much better, specifically when it comes to knowing where to be and how to find the soft spots in the defense. He's playing with more of a sense of urgency and his teammates have taken notice.
''You can ask any guy on the team, we've been seeing that from Dion since the spring,'' Wallace said. ''He's a whole different guy, he came in and lost weight, he's running a lot better and moving faster and I think the game is starting to slow down for him . It just opens up our offense because we have another threat.''
Notes: Cornerback Jamar Taylor (shoulder) and linebacker Jonathan Freeney (hamstring) are out for Sunday's game.
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