Week 21 Waiver Wire - Second Base (2B) and Shortstop (SS)

At this point, your league’s trade deadline has either passed or is almost here. That means for the remainder of 2018, you’ll be solely dependent on the waiver wire for any additions to your roster. Happily enough, RotoBaller is here to help you clinch a playoff berth or make a run toward the top spot in your roto or points league.

Every Sunday until the end of the season, we'll look at the best middle infielders available in at least 50 percent of Yahoo leagues. These are based on standard 5x5 scoring; adjust accordingly for your specific setup.

Let’s get to it. Below are your second base and shortstop waiver wire targets for Week 21.

Week 21 Middle Infield (MI) Waiver Wire Targets

Marcus Semien, SS, Oakland Athletics (49% owned)

Semien’s overall batting line stands at a modest .262/.321/.386, but he has notched double digits in home runs (10) and stolen bases (13) for the fourth consecutive season and is pacing toward 90 runs scored. He’s done this while running the best strikeout rate of his career to boot. The whiffs have gotten even more infrequent since the All-Star break, during which time Semien has hit .299/.382/.464 with three homers, three steals, and 32 R+BI in 26 games.

Willy Adames, 2B/SS, Tampa Bay Rays (33% owned)

Adames’ rookie season didn’t get off to a strong start, but he’s looked much better since the calendar flipped to August. In 15 contests so far this month, the 22-year-old has slashed .354/.418/.604 with three homers and four steals. Whiffs were a major issue for him early, and he’s cut his strikeout rate almost in half during this hot streak. He’s still hitting toward the bottom of the Tampa lineup, but it’s hard to see that continuing if he keeps this up.

Adalberto Mondesi, 2B/SS, Kansas City Royals (14% owned)

Mondesi has been a fixture on this list in recent weeks, but his ownership rate remains disproportionately low in comparison to his recent production. After another stolen base on Saturday, Mondesi is a perfect 11-for-11 on theft attempts in 20 games since the break. He’s also hitting .286 during that time. The run production is virtually nonexistent – such is life when you hit in the bottom third of the worst lineup in the major leagues – but Mondesi’s speed makes him worth rostering in plenty of formats.

Jorge Polanco, SS, Minnesota Twins (9% owned)

Polanco needed a few weeks to shake off rust after his suspension, but he’s flashed some of the form that helped him surge in the second half last year. The Twins’ shortstop is hitting .286/.347/.416 with two homers and four steals in 41 games since returning to the active roster. Polanco has found himself primarily slotted into the three-hole in the Twins’ lineup lately, so if he can send a few more balls over the fence, he’ll be a sneaky multi-cat contributor down the stretch.

Amed Rosario, SS, New York Mets (6% owned)

Rosario offers an alternative to Mondesi for owners who need speed if they’re also looking for run production, or just in an NL-only league. The Mets’ second-year man is hitting just .242 on the season, but he has swiped eight bags in nine tries so far in the second half, and he’s totaled 35 R+BI in those 26 games as well.

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