BoxRec

Adamek clearly won Arreola in their primes.
Prime Szpilka won past prime Adamek.
Now Arreola is past on his prime and Szpilka seems to be the better boxer after the Jennings loss,he trains with Ronnie Shields and looks very impressive.
His next fight with Ty Cobb is scheduled on April 25th.After that there are plans to compare him with Arreola on the undercard Huck-Glowacki at the turn of June/July.
My favorite is Szpilka,he should get decision there if he avoid row Arreola punches.
Szpilka trains with Ronnie Shields:
https://www.youtube.com/watch?v=xnz4WTEyuI4

It is a solid match-up. Szpilka is already starting to gain momentum towards a title shot with his win over Adamek, and if he beat Arreola as well, he would probably be about fourth in line for a shot after Fury, Wilder, and Glazkov. If Arreola were to win this, it would probably be his career-best win, topping the Seth Mitchell win. It is a closely-matched fight as well, though I'd have to favor Szpilka after seeing Arreola struggle with Curtis Harper.

Great fight. Edging with Arreola as Szpilka doesn't seem to hold a shot very well but can certainly see Szpilka moving to a decision.

Seems like a good match-up, though I'm not eager to see the winner against Wilder.