um- how much of aikido is atemi.
slide the hips to the right and backfist to the groin with the left hand. or
turning to the left bring the left elbow up to atemi the face. or
lift up one foot and stamping down atemi to their foot (making sure you scrape down the shin first- makes sure you locate the foot and don't stamp the ground).
either one of these provides an opening for technique (i'm sure there are many others)