Michael Aswell vs. JooSang Yoo: featherweight prelim preview at UFC 331

The setup

On Saturday, September 19, 2026, UFC 331 brings Michael Aswell (11-5-0) and JooSang Yoo (9-1-0) together at featherweight on the prelims at crypto.com Arena in Los Angeles, scheduled for three rounds.

Our schedule tables list 12 bouts on the card; this one is filed under the prelims. The bout is listed as announced in the PropBetEdge schedule.

The question this preview works through is simple: does either side bring a measurable edge, or is this a matchup the data leaves open? PropSports career averages are on file for both fighters, and the archive holds 5 completed UFC bouts for Michael Aswell and 2 completed UFC bouts for JooSang Yoo.

Tale of the tape

• Record: Michael Aswell 11-5-0 · JooSang Yoo 9-1-0
• Age: Michael Aswell 25 · JooSang Yoo 32
• Height: Michael Aswell 5'8" · JooSang Yoo 5'7"
• Reach: Michael Aswell 69" · JooSang Yoo 71"
• Stance: Michael Aswell Orthodox · JooSang Yoo Orthodox
• Listed weight: Michael Aswell 146 lbs · JooSang Yoo 152 lbs

Range is the first thing the tape flags: JooSang Yoo holds 2 inches of reach (71" to 69"), which sets the distance Michael Aswell has to cross to land. A reach edge matters most when the longer fighter also sets the pace, and here the numbers cut the other way: Michael Aswell out-lands Yoo 7.6 to 6.36 per minute, so the shorter fighter is the busier one and has to cross the gap to do it. That is a different fight from a long fighter picking apart a passive one. Michael Aswell is the younger by 7 years (25 to 32). Age on its own tells you little at this level; it reads better alongside the layoff figures in the form section. Both fight orthodox, so lead hands mirror and the rear-hand exchanges are conventional. Listed weights differ: JooSang Yoo at 152 lbs to 146 for Michael Aswell. Listed weight is a roster figure, not a weigh-in, so it is a note rather than an edge.

Recent form

Michael Aswell has 5 completed UFC bouts in the PropBetEdge archive: 1 win and 4 losses. That win came inside the distance. The losses went to the scorecards. Most recently he lost to Gaston Bolaños by unanimous decision in round 3 on Jun 20, 2026. That is 91 days before fight night, a quick turnaround.

• L vs Gaston Bolaños — unanimous decision, R3 (Jun 20, 2026, UFC Fight Night: Kape vs. Horiguchi 2)
• L vs Luke Riley — unanimous decision, R3 (Mar 21, 2026, UFC Fight Night: Evloev vs. Murphy)
• W vs Lucas Almeida — KO/TKO, R1 (Oct 11, 2025, UFC Fight Night: Oliveira vs. Gamrot)
• L vs Bolaji Oki — unanimous decision, R3 (May 31, 2025, UFC Fight Night: Blanchfield vs. Barber)
• L vs Bogdan Grad — split decision, R3 (Aug 28, 2024, Dana White's Contender Series: Season 8, Week 3)

JooSang Yoo has 2 completed UFC bouts in the PropBetEdge archive: 1 win and 1 loss. That win came inside the distance. He has been finished once in the archive, every loss ending early. He last fought on Oct 4, 2025 and lost to Daniel Santos by KO/TKO in round 2. That puts him 350 days out by fight night.

• L vs Daniel Santos — KO/TKO, R2 (Oct 4, 2025, UFC 320: Ankalaev vs. Pereira 2)
• W vs Jeka Saragih — KO/TKO, R1 (Jun 7, 2025, UFC 316: Dvalishvili vs. O'Malley 2)

Michael Aswell is the more recently active of the two (91 days out against 350 for Yoo).

Style and statistical matchup

Michael Aswell lands 7.6 significant strikes per minute at 42% accuracy; JooSang Yoo lands 6.36 at 58%. That 1.24-per-minute gap in Michael Aswell's favour is a real pace differential: over three rounds it compounds into a scorecard edge unless the lower-volume fighter is landing the more damaging shots. On the other side of the exchange, Michael Aswell absorbs 7.03 per minute with 52% striking defence and JooSang Yoo absorbs 4.99 with 56%.

On the ground, Michael Aswell averages 0.24 takedowns per 15 minutes at 25% accuracy and defends 55% of attempts against him; JooSang Yoo averages 0 at 0% and defends 50%. Neither fighter wrestles much by the averages, which points to a fight decided on the feet and makes the striking figures above the ones that matter.

All of these are career-to-date PropSports snapshots at capture, not as-of figures for this bout: they describe each fighter across every opponent, which is why the archive form above is read alongside them rather than replaced by them.

Round-level stats exist for 13 archived rounds of Michael Aswell's: 469 of 1102 significant strikes landed (43%), 36.1 per round, 1 of 4 takedowns, 4:42 of control time and 2 knockdowns. Round-level stats exist for 3 archived rounds of JooSang Yoo's: 37 of 63 significant strikes landed (59%), 12.3 per round, 0 of 0 takedowns, 0:00 of control time and 1 knockdown. Those samples are small and uneven, so they colour the career averages rather than override them.

What could break the angle

Start with what is missing. JooSang Yoo has only 2 archived UFC bouts in the PropBetEdge database, so the form read is thin. Career averages are career-to-date snapshots at capture; they include fights outside this matchup context and are not as-of figures. There is also no odds snapshot in PropBetEdge data for this bout, so nothing above can be checked against a market yet; the read describes what to look for, not where value sits. A late weigh-in miss, a replacement or a change in scheduled rounds would each invalidate parts of it.

Final read

On the data, neither fighter carries a material edge into this one; the tape is close and the archive does not separate them. The uncertainty is mostly about coverage: archive shorter than 3 bouts for JooSang Yoo. What to monitor: the three-round format holding, the weigh-in, and once a price exists, where the significant strikes market opens relative to this read. No model price or market line exists in PropBetEdge data for this bout, so this is not a pick; the Bettor's Edge panel above carries the impact score and the markets connected to the evidence.

Matchup page: Michael Aswell vs. JooSang Yoo · Full card: UFC 331: Van vs. Pantoja 2 · Fighter pages: Michael Aswell, JooSang Yoo.