Will Orioles protect Isaac Mattson from Rule 5 draft?

The internal discussions in the Orioles organization related to Friday's deadline for setting the 40-man roster expand beyond the prospect lists that are blooming in the fall.

You won't find reliever Isaac Mattson in the top 30 published by MLBPipeline.com.

You could find him among the protected players.

There's room on the bubble for Mattson and, without any inside information, I'm predicting that he goes on the 40-man along with outfielder Yusniel Diaz and pitchers Michael Baumann and Zac Lowther.

(Others eligible, as I'm sure you've heard, include pitchers Alexander Wells, Cody Sedlock and Zach Pop and infielder Rylan Bannon.)

Mattson just feels like a guy who's too close to the majors to risk losing. Perhaps he would have debuted in a non-pandemic summer after impressing at Triple-A Norfolk, but we'll never know.

Workouts and intrasquad games at the alternate camp site in Bowie kept Mattson busy over the summer. Norfolk pitching coach Kennie Steenstra, one of the instructors at Prince George's Stadium, described Mattson as "very impressive."

Executive vice president/general manager Mike Elias traded for Mattson and three other minor leaguers in the Angels system, a nice return for former first-round pick Dylan Bundy.

Mattson, now 25, was a 19th-round pick in 2017 out of the University of Pittsburgh who made a combined 37 relief appearances between Single-A-Inland Empire, Double-A Mobile and Triple-A Salt Lake last year and went 6-3 with a 2.33 ERA and a 1.009 WHIP. He averaged 13.5 strikeouts per nine innings and opponents batted .184.

The Orioles were able to scout Mattson in the Arizona Fall League, where he allowed two earned runs and struck out 12 batters in 10 2/3 innings.

"I would say Mattson was the one with whom I was the least familiar," Elias said on the day of the trade, "but you look at his numbers, he's been really dominant across the minor leagues and especially lately just dominant wherever you send him, including the Arizona Fall League. We feel that he might be somebody that we can see up here to help our team next year."

Mattson didn't get the call from the alternate camp site, which surprised me, but he impressed prior to joining the organization. The high spin rate on his fastball and career 10.9 strikeouts per nine innings attracted the Orioles like moths to a flame.

I remember the exhibition game against the Rays in Port Charlotte when Mattson, invited from minor league camp, inherited a bases-loaded jam from Branden Kline and retired Yandy Díaz on a ground ball. And the strikeout he recorded against the Blue Jays in Dunedin after replacing Hunter Harvey.

Danny Jansen tripled and was stranded.

The Orioles have done a nice job of determining which players are safe outside the 40-man. The ones who are likely to be bypassed or stand little chance of remaining with a team for the entire season.

They haven't lost a player in the major league phase since first baseman Ji-Man Choi in 2015 and the Orioles had him for less than three weeks. The signed him as a free agent and didn't protect him, and the Angels made the selection to close the round.

Prior to Choi, the last players chosen from the organization were pitchers Pat Egan and Pedro Beato in 2010. The Brewers returned Egan, who never reached the majors.

The theory about expanded rosters making it easier for teams to stash players is a mathematical truth and Mattson could be more vulnerable to a claim. He also could have a better shot at pitching for the Orioles.

They don't have every spot accounted for in 2021 and Mattson could find a seat on the shuttle or earn a longer stay.

He was the closest to being ready for the majors when Elias swung the trade.

The Orioles must try to determine, by whatever methods, whether he needs protecting this week.