Strange drop in performance?

One of my athletes set a PB in the 100 14 days ago. In the same race she got a minor injury in her foot, which meant that during the following 9 days she did little volume with low intensity.

Wednesday (four days ago) after getting the green light from our physician she returned to training, doing a full sprinting program. Thursday she did long jump technique and strength.

This is usual procedure for her - nothing out of the ordinary here.

Saturday she started (yesterday) she ran a 100 again. Conditions were good, but she ran 0.4 s slower than her PB(!)

The race looked sound technically, but her Ground Contact Time seemed a bit slower than usual.

A summary:

18: PB
19: Travel
20: Rest
21: Low volume jumping and strength
22: Rest
23: Some sprinting and jumping - cut short because of minor pain
24: Rest
25: Rest
26: Low intensity, low volume - auxillary drills
27: Rest (cleared to train and compete)
28: Max sprinting
29: Long Jump technique, Strength (complex)
30: Rest
1: Competition

On 23 and 29 I noticed she threw app. 1 meter below normal standard in the backwards shot throw (Lyakhov).

So what to make of it?

The planning for this season has been based on conjugate principles. She trains 4-5 times a week - almost exclusively high intensity.
During the 6 weeks prior to her PB we did some plymetric jumps once a week. This has been dropped since her PB.

Once-twice a week we have been doing strength sessions with deep squats (~85%), hanging snatch (~20%), step ups (no load), jump squats and hurdle jumps.

Sprinting has been low volume until now - once-twice a week.

I have been able to come up with three possible explanations:

  1. Nine days with almost no CNS stress, followed by two days of high CNS stress (but normally not unusual for her) prior to competing resulted in a tired CNS.

  2. Her PB came in a very important meet - her first international appearance. Two days later she had her final exam - all in all a very mental draining scenario - possible impact?

  3. The conjugate planning with almost exclusively high intensity training has resulted in a “burned out” CNS.

Maybe there could be other explanations. There’s no apparent signs of infection or anything similar.

There’s 10 weeks until her next major objective for the season. If the dropp off is caused by “3”, I have to rethink the planned approach for the major meet.

Any suggestions, explanations etc.?