After signing high school first basemen Anthony Rizzo (sixth round, $325,000) and David Mailman (seventh round, $550,000) earlier on Deadline Day, the Red Sox have announced four more over-slot signings.

Most notably, Boston landed fifth-round third baseman Will Middlebrooks, considered to be a supplemental first-round talent for $925,000. The Red Sox also signed 16th-round righthander Austin Bailey ($285,000), 17th-round first baseman/outfielder Jaren Matthews ($250,000) and 23rd-round lefty Drake Britton ($700,000).

Editor’s note: Though he agreed to terms that were submitted to the commissioner’s office, Matthews later changed his mind about signing. No word on how this will affect his NCAA eligibility, as he plans to attend Rutgers.

Scouting reports on all six players, from our Draft Preview:

• Will Middlebrooks, 3b/rhp, Liberty-Eylau HS, Texarkana, Texas

Kevin Ahrens isn’t the only blue-chip third-base recruit Texas A&M could lose to the draft. Where Ahrens gets compared with Chipper Jones, the more athletic Middlebrooks draws Cal Ripken Jr. and Scott Rolen comparisons. Selected to play in a Texas high school football all-star game, Middlebrooks drew college interest as a quarterback and punter. He’s also a 6-foot-4, 215-pound righthander with a low-90s fastball and an occasional plus curveball. But his future is at the hot corner. He’s not quite as polished a hitter as Ahrens, but he’s not far off and his size gives him leverage that will produce power. He’s an athletic third baseman with good range and a strong arm, and he runs well for his size. Middlebrooks is a consensus supplemental first-rounder, but he could sneak into the first round with the right club.

• Anthony Rizzo, 1b/lhp, Douglas HS, Parkland, Fla.

Anthony Rizzo also has plus raw power, but lacks fluidity in his swing and is relegated to first base as a professional. He performed well enough on big stages with a wood bat to be a factor in the fifth round, while some other teams have expressed no interest in drafting him.

• David Mailman, 1b, Providence HS, Charlotte, N.C.

Not unlike the sentiment regarding fellow North Carolina prep prospect Justin Jackson, Mailman’s future as a professional draws a wide range of opinion. He has a smooth lefthanded swing that appears to have lots of power projection, but whether his thin frame fills out is the question stumping most scouts. His approach is quiet and balanced, as he uses the entire field and shows the beginnings of an ability to lift balls out of the park. Based in part to a lack of strength, his bat speed is fringy at present and he can be beaten with good fastballs above his hands. He’s a below-average runner but a plus defender, with good footwork around the bag and confidence handling throws in the dirt. He has a solid-average arm. Mailman also has championship-caliber makeup, and fits the profile of a potential college masher if he honors his commitment to Wake Forest. It might require third-round money to get him signed this spring.

• Austin Bailey, rhp, Prattville (Ala.) HS

When Bailey hooked up with an East Cobb (Ga.) travel team as an underclassman, he proved he was capable of competing with the best high school players in the country. He’s a strong, undersized athlete with good tools on both sides of the game. His arm strength is his best asset. He has an aggressive mentality and comes right after hitters with a three-pitch mix. His fastball ranges from 88-93 mph. His secondary stuff is fringy, though he’ll flash a curveball with depth and tight rotation. He has rudimentary feel for his changeup. He’s still mostly a thrower and lacks much feel for pitching. Because Bailey doesn’t project to get much bigger or throw much harder, he’s considered a third- to fourth-round talent. Judging his signability has been difficult, and if he slips past the fifth round he could elect to attend Alabama.

• Jaren Matthews, 1b/of, Don Bosco Prep, Teaneck, N.J.

Jaren Matthews can light up workouts, but he doesn’t show much feel for the game. He has a plus arm, solid-average bat speed and plus raw power, but doesn’t make consistent hard contact, and his lefthanded swing has holes.

• Drake Britton, lhp, Tomball (Texas) HS

Texas’ high school lefthander crop isn’t strong this year, and the top prospect has been inconsistent this spring. Drake Britton has battled his delivery and his command, and his fastball has ranged from 85-88 mph at times to 89-92 at others. He throws from a low arm angle, which makes it tough to stay on top of his slider. He wants top-two-rounds money early in this year, and he won’t get that now. He’s a prime candidate to be drafted and followed during the summer. He’ll go to Texas A&M if he doesn’t turn pro.